美国考试用什么搜题
1-8,14,15,17
统计有三种涵义，其中（ ）是基础。
对某市高等学校科研所进行调查，统计总体是（ ）
要了解某市全民所有制工业企业设备情况，则统计总体是（ ）
要了解50个学生的学习情况，则总体单位是（ ）
标志是指（ ）
统计的特点有：（ ）
数量指标反映总体某一特征的（ ）
下列标志中，属于数量标志的有（ ）。
下列标志中，属于品质标志的有（ ）。
下列各项中，哪些属于统计指标（ ）
统计着眼于事物的整体，不考虑个别事物的数量特征。 （ ）
统计学是一门实质性社会科学。 （ ）
一个人口总体，可以用人口总数，年龄、性别、民族等概念来反映和描述。 （ ）
诸如粮食产量、身高等，是离散变量，它们的数值可以靠计数取得。（ ）
统计学是一门（ ）、（ ）和（ ）统计数据的方科学。
标志按其表现形式不同，有（ ）标志和（ ）标志之分。
变量按其数值是否连续，有（ ）变量和（ ）变量之分。
变量是指（ ）数量标志和指标。
按统计指标的作用和表现形式不同，可分为（ ）、（ ）、（ ）。
某手机厂商为了掌握该厂的产品质量，拟进行一次全厂的质量大检查，这种检查应当选择（ ）。
某地区为了掌握该地区化肥生产质量情况，拟对占该地区化肥总产量80%的五大化肥厂的生产情况进行调查，这种调查方式是（ ）。
对一部分农民家庭收支状况通过提问，算帐方式进行调查，这是采用统计调查中的（ ）。
人口普查规定统一的标准时间是为了（ ）。
下边哪种现象适用于一次性调查（ ）。
抽样调查和典型调查的主要区别有（ ）。
在我国专门调查有（ ）。
我国第六次人口普查属于（ ）。
下列情况的统计调查，哪些属于经常性调查（ ）
常用的搜集统计资料的方法有（ ）。
统计调查中的调查单位与填报单位是一致的。（ ）
调查时间指的是统计调查工作的起止时间。（ ）
重点调查可以是定期的，也可以是不定期的。（ ）
准确性是统计调查最基本的要求，所以统计资料必须100%准确才能有效发挥作用。（ ）
统计调查按调查对象包括的范围不同，可以分为（ ）与（ ）。
统计调查按调查登记的时间是否连续，可以分为（ ）与（ ）。
普查是一种（ ）的（ ）调查。
按调查组织方式不同，统计调查可分为（ ）和（ ）。
统计调查的要求是（ ）、（ ）、（ ）。
如果我们所需研究的是整个工业企业职工人员的状况，则总体单位总量是（ ）。
某种产品单位成本计划规定比基期下降3%，实际比基期下降3.5%，单位成本计划完成程度相对指标为（ ）。
权数本身对加权算术平均数的影响，决定于（ ）。
众数是由变量数列中（ ）。
平均差与标准差的区别主要是（ ）。
国有企业的工业增加值（ ）。
比较相对指标可用于（ ）。
下列数列中，可以计算算术平均数的有（ ）。
标准差（ ）。
总体单位总量和总体标志总量会随研究目的的不同而转化。 （ ）
当各变量值的连乘积等于总比率或总速度时，宜采用几何平均法计算平均数。（ ）
比较两总体平均数的代表性，标准差系数越大，说明平均数的代表性越好。
实物指标的综合性能差，而价值指标的综合性能好。 （ ）
总量指标按其反映的时间状况不同，可分为（ ）和（ ）。
强度相对指标数值大小，如果与现象的发展程度成正比，称之为（ ），反之称为（ ）。
总量指标按其反映的内容不同，可分为（ ）和（ ）。
加权算术平均数受两个因素的影响，一个是分布数列中（ ），另一个是（ ）。
下列属于时点数列的是（ ）。
某种产品的产量2011年－2015年分别比2010年增长30、40、45、60、80万吨，这五年间平均每年增长量为（ ）
下列等式中，不正确的是（ ）
序时平均数与一般平均数的共同点是（ ）。
几何平均法平均发展速度数值的大小（ ）。
直线趋势yt=a bt中a和b的意义是（ ）。
编制时间序列的原则有（ ）。
动态平均数包括（ ）。
对于季节变动的测定，下列说确的是（ ）。
下列哪些是反映平均指标变动的指数（ ）
时间数列的发展水平就是总量指标。（ ）
在时间数列中，报告期水平与基期水平的确定总是与一定研究目的相联系的。（ ）
若各期的逐期（环比）增长量△相等（△>0），则各期的环比增长速度是逐年（期）增加的。（ ）
平均增长速度不是根据各期环比发展速度直接求得的，而是根据平均发展速度计算的。（ ）
时间数列一般由（ ）和（ ）两个基本要素构成。
时间数列的分析指标可分为（ ）和（ ）两大类。
发展速度由于采用的基期不同可分为（ ）发展速度和（ ）发展速度两种。
如果移动时间长度适当，采用移动平均法能有效地消除循环变动和（ ）。
统计指数划分为个体指数和总指数的依据，是按指数（ ）。
综合指数是（ ）。
总指数编制的两种形式是（ ）。
某造纸厂产量比上年增长了13.6%，生产总费用增加了12.9%，则该厂产品单位成本（ ）。
在由三个指数所组成的指数体系中，两个因素指数的同度量因素通常（ ）。
综合指数与加权平均指数关系在于（ ）。
下列指数中属于质量指标指数的是（ ）。
若用p表示价格，q表示商品销售量，则公式∑p1q1-∑p0q0的意义是（ ）。
综合指数与平均指数的区别与联系表现为（ ）。
某产品的生产总成本2014年为20万元，比2013年多支出0.4万元，单位成本2014年比2013年降低2%，则（ ）
反映数量指标变动的个体指数和总指数都称为数量指数。 （ ）
平均指数这种编制总指数的方法，即可用于全面调查的资料，又可用于非全面调查的资料。
为使成本指数的计算符合现实经济意义，则编制单位产品成本指数的同度量因素是基期的产品产量。
平均指标指数是由两个平均指标对比形成的。
总指数的编制方法，其基本形式有两种：一是（ ），二是（ ）。
编制数量指标综合指数的一般原则是采用（ ）作为同度量因素。编制质量指标综合指数的一般原则是采用（ ）作为同度量因素。
在指数体系中，指数之间的数量对等关系表现在两个方面；一是对象指数等于各因素指数的（ ）；二是对象指数的分子项与分母项之差等于各因素指数的（ ）。
所谓随机原则，就是指（ ）。
抽样误差（ ）。
下列各种社会经济现象属于变量总体的是（ ）。
抽样调查与全面调查的关系是（ ）。
为了了解某地区职工的劳动强度和收入状况，并对该地区各行业职工的劳动强度和收入情况进行对比分析，有关部门需要进行一次抽样调查，应该采用（ ）。
在抽样估计中（ ）。
计算抽样平均误差时，由于总体方差是未知的，通常有下列代替方法（ ）。
样本容量的大小（ ）。
对一个正态总体进行抽样调查，不管样本量大小如何，样本均值总是服从正态分布。（ ）
抽样极限误差总是要大于抽样平均误差。 （ ）
若要估计即将毕业的在校大学生对就业感到乐观者所占的比例，在全国100所重点大学中每所大学分别随机抽取25个男生和25个女生，共计抽取5000名学生构成样本。这样的样本应该具有较好的代表性。（ ）
根据抽取样本的方式不同，抽样方法有（ ）和（ ）两种。
抽样的组织形式主要有（ ），（ ），（ ），（ ）和（ ）五种形式。
估计量的优良性标准有（ ）、（ ）和（ ）。
按设计标准，某自动食品包装机所包装食品的平均每袋重量应为500克，若要检验该机实际运行状况是否符合设计标准，应该采用（ ）。
假设检验的p值表示（ ）。
假设检验中，显著性水平表示（ ）。
设总体为正态总体，总体方差未知，在小样本条件下，对总体均值进行如下的假设检验，h0：µ=µ0（µ0为一已知数）；h1：µ:≠µ0，α=0.1，则下列说确的有（ ）。
利用z统计量可以对总体比例进行假设检验，则下列说法中正确的是（ ）。
下列关于检验统计量的正确说法有（ ）。
假设检验是一种科学的统计决策方法，因此使用它不会犯错误。（ ）
在假设检验中，如果在显著性水平0.05的前提下拒绝了假设h0：µ≤µ0，则在同一水平一定可以拒绝假设h0：µ= µ0 。（ ）
在做假设检验时容易犯的两类错误是（ ）和（ ）。
有一批电子零件，质量检查员必须判断是否合格，假设此电子零件的使用时间大于或等于1000，则为合格，小于1000小时，则为不合格，那么可以提出的原假设和备择假设分别为（ ）和（ ）
进行相关分析，要求相关的两个变量（ ）
当x按一定数额增加时，ｙ也近似地按一定数额随之增加，那么可以说x与ｙ之间存在（ ）关系。
对于相关系数，下列描述不正确的是（ ）
相关分析和回归分析相辅相成，又各有特点，下面描述正确的有（ ）
下列现象属于相关关系的是（ ）
判定现象之间有无相关关系的方法是（ ）
在回归方程中，回归系数（ ）
不管相关关系表现形式如何，当|r|=0时，变量x和变量y都是完全不相关。（ ）
不论是相关分析还是回归分析，都必须确定自变量和因变量。（ ）
对于表现为因果关系的相关关系来说，自变量一般都是确定性变量，因变量则一般是（ ）变量。
回归方程中估计待定参数最常用的方法是（ ）。
which sentence is not recommended in a business letter?
which of the following sentences are better?
to make your writing effective, you should
which of the following sentences following you-view point?
which of the following sentences take a positive tone？
which of the following sentences is correct？
which of the following parts are standard parts of a business letter？
which part of the letter can help the reader to obtain the gist of the letter quickly?
the principles of good business writing are___________________________
to write effectively, you need to identify your readers. so before writing, you should know___________.(more than one correct choices)
which sentences follow the concreteness principle? (more than one correct choices)
which sentences follow the clarity principle? (more than one correct choices)
which sentences follow the conciseness principle? (more than one correct choices)
作业题1: please arrange the following parts of a business letter into the correct order. 1) sender’s name: shanghai chemicals trading co.ltd. 2) sender’s address: 76 fuxing road, shanghai 200030,china 3) sender’s telephone number: 021-61000000 4) sender’s fax number: 021-61000001 5) date: may 18, 2010 6) receiver’s name: precise instruments, inc. 7) receiver’s address: 202 37th street, new york, ny 10016,us 8) subject: hand tools 9) the message: we are interested in hand tools suitable for home decorating and would like to have details of your prices and terms. it would be helpful if you could supply samples. 10) complimentary close: sincerely yours
完成以下英文信件的写作。 格式：齐头式 信头：本字和地址 封内地址：纽约市第50大街10号 harper & row出版公司 邮编：ny10022 写信日期：实际日期 信文内容： 从朋友处看到《成功的商务沟通》一书。 为提高写作水平欲购一本。 请出版商尽快告知付款方式 希望9月底收到此书
can you quote _____ 1000 bicycles we enquired for in our letter of march 13?
we are a leading corporation _____ industrial chemicals, and would like to have the details of your products.
we are one of the largest exporter of textiles in our country and have been ____________________for more than ten years.
in the trade terms cfr, “c” stands for ______.
we are writing on behalf of our french principals, who are now _____ office furniture.
if your samples meet our requirement, we will _____ a large order.
we look forward to _____.
we would _____ if you would send us an up-to-date price list for your building materials.
we are interested in _____ a number of prominent manufacturers in your country with a view to _____ lines suitable for the american market.
full information as to prices, quality, quantity _____ and other relative particulars would be appreciated.
we are sending you a representative selection of our most popular lines and you will find a ready _____ for them.
the goods are urgently needed. we ______ hope you will deliver them immediately.
we place this order ______ the understanding that the discount is 10%.
we regret to inform you that our computers are ____________ .
if the _________________ proves to be successful, many orders will follow.
if your prices and qualities are satisfactory, we will place a _____ order with you.
enclosed please find our purchase confirmation no.8848___________.
we are sending you, under ______, by airmail a copy of the latest catalogue.
your firm has been ______ to us by crombongo textiles co. ltd, with whom we have done business for many years.
______ please find our latest products catalogue.
______ your prices are suitable, you will find a ready market for the products.
we should stress that this is the first order with your firm, and if satisfied, we would place ___________________.
thank you for your order no.123. we _______________ it and will dispatch th goods early june.
please open the relevant l/c in time to ensure the _________________of the order.
假设你公司收到abc公司数码照相机(digital camera)的价格表和样品，对报价(quotation)和产品质量感到满意，决定订购。请你写一封订购信，告诉对方订购数量、价格、货运期、付款方式，并希望来函确认订购。
tramps are ready at any time to_________ any particular voyage.
shipping agents will _________the goods to be shipped.
what are the common ways to convey the goods to their destination?
eta refers to _________________________.
we should be _________ if you would send us by air a copy of the packing list for the shipment.
we also ask you to see to _________ that all the goods are well packed, so as to avoid damage in transit.
we are in urgent need of the cargoes. _________you ship them by direct steamer?
we find _________transshipment and partial shipments of the goods are not acceptable.
it will be appreciated _________you could effect shipment in two equal lots by direct steamer_________ you receive our l/c.
we helped them_________ the shipping marks.
please note that the goods can be certainly promised for immediate shipment _________ receipt of your covering l/c.
the shipment must be effected within the prescribed time limit, as a further_________ will not be considered by our customers.
please advise us of the steamer that call _________ your port every month.
tramps are ready at any time to_________ any particular voyage.
before deciding which form of transport to use, a_________ will take into account the cost, speed and safety.
shipping agents will _________the goods to be shipped.
for ________ commodities as oil, sand and timber, rail is cheaper than road.
we have great pleasure in making you a special ____ for 300 bottles of body lotion in beautifully-designed display packages.
this offer is firm, _____ your confirmation reaching us before or on june 16.
_____ orders of 1000 pieces or more we _____ a special discount of 4%.
the seller may cancel the contract and reserve the right to claim _________buyer’s breach of contract.
_________ the above, we would suggest that you accept our original offer without any delay.
please note that the items marked with a tick can be supplied _____ stock.
the above quotations are made _____ the basis of cif karachi, but a discount _____ 5% may be allowed if the quantity for inidual item reaches 1,000.
_____ orders of 1000 pieces or more we _____ a special discount of 4%.
this offer is firm, _____ your confirmation reaching us before or on june 16.
a quotation is a written form response to an enquiry, telling the enquirer the price and other terms of transaction. in this sense, the term “_____” is often used as “quotation” in international trade, today. however, in practice, _____ is usually a “_____”.
the seller may cancel the contract and reserve the right to claim _________buyer’s breach of contract.
could you make us a firm offer_________ shoes?
the above offer is _________ engagement.
_________ the above, we would suggest that you accept our original offer without any delay.
shipment is to be made _________ 3 months on receipt of the relative l/c.
we should like to have the insurance _________ for 110% of the invoice value.
the cargo is to be insured _______ warehouse _______ warehouse against all risks.
we are pleased to confirm _________ the above goods for us$4000.
we are also in a position to insure the shipment_________ any additional risks if you desire so.
we should like to have the insurance _________ for 110% of the invoice value.
please insure f.p.a. ______ your end.
we shall provide such coverage _________ your cost.
if any damage occurs a claim may_______ with the insurance agent at your area.
your l/c calls for an insurance amount for 150% of the invoice value. _________, we would request you to amend the insurance clause.
the cargo is to be insured _______ warehouse _______ warehouse against all risks.
we are pleased to confirm _________ the above goods for us$4000.
picc stands_________ the people’s insurance company of________.
damage _________the goods was caused by heavy rain _________transit.
insurance is to be_________ by the seller if a transaction is concluded on cif basis.
extra premium is for buyer’s account, _________additional risks be covered.
we wish to _________the above policy for the same amount and on the same terms _________ before to cover our consignment to be shipped by s.s. east wind next month.
this kind of additional risk is coverable_________ a premium of 0.2%.
insurance is to be covered _________ invoice value plus 10%.
our package for canned fruit is not only seaworthy but also strong enough to protect the goods ______ possible damage.
we will pack your fresh vegetable ______ bundles of suitable size for shipment.
flowers are packed 10 pieces _____ a box and 100 box _____ a wooden case.
this is to apply ______ all orders unless otherwise specified.
overall ______ of each case must not exceed 2×1×1.5m.
we are ______ to measuring the weight of oil by barrel instead of kilograms.
the goods must be packed in requested containers so as to avoid damage ______ the goods.
we will pack the goods _______our usual practice if we do not hear from you to the contrary.
the client suggested that the packing of this article ______ improved.
with ______ to the shipping marks, the supplier should follow the instruction of the buyer.
garments are generally packed in plastic ______ cartons.
you know that the appearance of the package ______ greatly to the sale of consumer goods.
our package for canned fruit is not only seaworthy but also strong enough to protect the goods ______ possible damage.
the goods you packed in wooden cases are ______ to damage by moisture.
flowers are packed 10 pieces ______ a box and 100 boxes ______ a wooden case.
please see to it that the ______ must be strong enough to withstand rough handling.
the third shipment of blankets against order no.cv323 is also to be delivered. please take _______ measures against any damage in transit.
in a l/c transaction, payments are made in exchange for _____.
we are asking you to _____ your l/c to read "transshipment allowed".
_____ is the chief means which is now most often used in the settlement of payment in international trade.
under _____, the seller can feel assured that so long as he has made the delivery of the goods and got the required documents he can get the payment of the goods in time and the buyer can also feel at ease that he can get the shipping documents at the same time when he effects the payment of the goods.
_____ is usually a bank in the country of the importer.
in international trade, traders usually use _____ for the payment of the goods.
in a l/c transaction, payments are made in exchange for _____.
the l/c is to be opened before july 10, 2004. the beneficiary’s draft shall be drawn against the l/c ______ by the following documents.
provided you fulfill the terms of the l/c we will _____ the draft drawn under this credit.
for future business in all amounts, we may consider _____ shipment on d/p basis.
as instructed by you, we have opened a letter of credit _____ your account _____ favor of xxx company, valid _____ march 9, 2009.
we have _____ the shipment and validity dates of the l/c to october 15 and 30 respectively.
please give us a month’s _____ if you wish to change delivery time.
we are asking you to _____ your l/c to read “transshipment allowed”.
you may _____ us at 60 days for the amount of the invoice.
once a business relationship was established, your accounts would be _____ by 60-day bill of exchange, documents against payment.
having checked your l/c, we find that several points are not in _____ our s/c no.1234.
if a customer is dissatisfied with the execution of his order, he will _____.
if a claim is justified, timely and well-supported, it should be _____ promptly and carefully.
in international trade, when issues occur resulting from misunderstanding or accidents, the party that suffers losses will surely make a(n) _____, asking for compensation.
you would be adequately _____ if the goods should be found defective.
we are grateful to you for the order, but _____ that we cannot allow a further discount of 3%.
unfortunately, we cannot send you a full range of samples at present, but you may rest _____ that the products are of the same high quality.
we can _____ the damaged parcel, or we can give you a 9% discount.
the ship did not arrive on time, _____ was its departure _____.
we are sorry to learn from your letter of june 2 that you have had complaints _____ customers _____ our silk.
when customers receive the goods _____ quality, they may make a complaint or file a claim against the supplier.
if one party violates or fails to carry out the contract, the other party is entitled to claim indemnity for any loss or damage. the underline part of the sentence means_____.
what is usually the first solution to a business dispute?
we regret to have to lodge a complaint against you about our loss arising from your late delivery of the coffee supplies we purchased under our order no.op7836. the word underlined can not be substituted for by the following:
if cargoes cannot be found within a few days, we will file our claim for the full _________ of them.
we have to file a claim against you ________ us$15,000.
when looking into the case, we found that the goods did not agree _______the original sample.
if you want to make your sales letter effective. what should you probably do in your opening?
which of the following is the most effective closing for a sales message?
which of the following illustrates a testimonial?
which of the following most effectively illustrates reader benefits and elicits desire?
techniques to elicit audience desire and overcome reader resistance in a marketing message include all of the following except
professional marketers and salespeople follow the aida strategy in their sales letters because it is effective. what does aida represent?
testimonials used in your online sales message are best sprinkled throughout the copy.
your e-mail sales message must have a formal, concise, clear subject line such as price list fall 2014 from parker and parker.
you will receive a free one-year subscription to netflix when you purchase any sony flat-panel television is an example of a rational appeal.
the unique selling points (usps) of a product are the things that make it special and different from other similar products.
you should make the readers realize that not only the product or service is good, but it is good for them (linked to certain needs of the reader).
见附件
in the letter of invitation, what does “r.s.v.p.” stand for?
which of the following principles is not true in the writing of invitation card?
which of the followings is true according to the principles of the writing of invitation letter?
the formal expression of “恭请……光临” in english can be _________________.
which of the following is not the occasion for writing a thank-you letter?
which of the following is not a sentences for general appreciation or sincere personal comment?
what should not always be a thank-you letter’s main points?
even if you are not the successful candidate, you can write a thank-you letter to make a on the employer.
a congratulation letter should be full of .
thank you for the time and consideration you to me during my interview with you yesterday.
i appreciate had the opportunity to speak with you about my experience in related fields and my future goals.
which of the following items is wrong in explaining a notice?
which of the followings does not belong to the categories of a notice?
which is wrong in writing a notice?
combination resumes are a combination of both ________________.
a ________, is also called curriculum vitae (cv).
i have five years of ______ experience with elite designers.
which of the following are not the general formats of resume?
which of the following statement is not true about cover letter?
which of the following are necessary part to be included in a resume?
a resume is a self-advertisement that can show your skills, experiences, and achievements.
career objective is best for mid-level candidates.
you’d better list your work experiences in reverse chronological order.
you need to tailor your resume to every job application.
in your cover letter you can simply repeat what are on your resume.
if you applying for a particular position your cover letter will need to be tightly focused to explain your suitability for that job.
when write a cover letter you don’t need to bother the name of the person in hr to address the letter to.
reports that present data without ysis or recommendations are____________.
which of the following is most likely to be written as an informative report?
which of the following reports is an example of an ytical report?
when you organize a report indirectly, in which order should you present your ideas?
you are writing a short, informal report that will stay inside your organization. which format would be most appropriate?
headings that show the outline of a report are called____________
why the recommendation part is the most important part of a brief business report?
typical sources for factual information in an informal report include__________
which of the following represents the best use of language in report writing?
to make your report effective, you should ___________.
in most cases, a report includes___________.
the introduction part of a brief business report has the following components____________
the most common type of report in the workplace is the formal report.
based on their function, business reports typically fall into one of two categories: instructional or persuasive.
the first step in preparing a report is to sit down and begin writing immediately; this technique allows you to capture your best ideas quickly.
when your reader may oppose your recommendation, you should begin the report by announcing the recommendation directly.
电码的发明者是（ ）。
（ ）发明了电磁波。
电子线路的心脏器官是（ ）。
调幅简称为（ ）。
（ ）是无线通信的传输媒质。
无线电波中的（ ）是高频段的缩写。
无线电波的毫米波的波长范围是（ ）mm。
调制是指（ ）的某一参数。
解调是从（ ）。
非线性电路会产生新的频率成分。（ ）
非线性电路能用叠加定理分析（ ）。
选频网络在有些电路中可当做负载使用。（ ）
低频信号可直接从天线有效的发射。
为了有效地发射电磁波，天线尺寸必须与发射信号的波长相比拟。
电视、调频广播和移动通信均属于短波通信。
（ ）是通信电路中最常用的无源网络。
选频利用了lc谐振回路的（ ）特性。
lc回路的谐振曲线越尖锐，选择性越（ ）。
选择性是指谐振回路（ ）的抑制能力。
通频带与回路q值（ ）。
矩形系数是一个（ ）的数。
并联谐振回路谐振时，谐振导纳（ ）。
一个单一的并联谐振回路的矩形系数接近于（ ）。
阻抗变换电路是一种将（ ）所要求的最佳负载阻抗的电路。
并联谐振回路发生谐振时阻抗最大且呈现纯阻性。（ ）
选频网络在电路中有时可以当做负载使用。（ ）
串联谐振回路发生谐振时回路电流最小。（ ）
阻抗变换电路的作用是减小信号源内阻及负载电阻对谐振回路的影响。（ ）
通频带是指回路端电压下降到最大值的1/2时所对应的频率范围。（ ）
lc并联谐振回路带载后，通频带会变宽，选择性变差。（ ）
下列不属于高频小信号放大器技术指标的是（ ）。
在谐振放大器的lc回路并联一个电阻r，可以（ ）。
小信号谐振放大器不稳定的原因是（ ）。
谐振放大器采用部分接入的原因是（ ）。
多级单调谐小信号放大器级联，将使（ ）。
三极管的y参数中体现三极管放大能力的参数是（ ）。
谐振放大器处在谐振时其增益最大。（ ）
谐振放大器矩形系数越接近于1，则放大器的选择性越好。（ ）
多级耦合的调谐放大器的通频带比组成它的单级单调谐放大器的通频带宽。（ ）
调谐放大器兼有选频和放大功能。（ ）
多级耦合的调谐放大器的通频带比组成它的单级单调谐放大器的选择性差。（ ）
谐振放大器是采用谐振回路作负载的放大器。（ ）
通频带与回路q值是互相矛盾的两个性能指标。（ ）
对于设计好的放大器，其增益带宽积为常量。（ ）
谐振电压增益振幅与谐振回路总电导gσ有关。（ ）
影响丙类谐振功率放大器性能的主要参数不包括（ ）。
功率放大电路根据以下哪种说法可分为甲类、乙类、甲乙类、丙类等。（ ）
欲提高功率放大器的效率，应使放大器的工作状态为（ ）。
某丙类谐振功率放大器工作在临界状态，若保持其他参数不变，将集电极直流电源电压增大，则放大器的工作状态将变为（ ）。
利用高频功率放大器的集电极调制特性完成功放和振幅调制，功率放大器的工作状态应选（ ）。
谐振功率放大器输入信号为余弦波，放大器工作在临界状态时，集电极电流为（ ）。
利用高频功率放大器的基极调制特性完成振幅调制，功率放大器的工作状态应选（ ）。
谐振功率放大器与谐振小信号放大器的区别是（ ）。
高频功放的动态线是一条直线。（ ）
功率放大器是大信号放大器，要求在不失真的条件下能够得到足够大的输出功率。（ ）
高频功率放大器是非线性放大。（ ）
高频功率放大器采用谐振回路作为负载。（ ）
直流馈电线路的作用是为高频功放电路的输入和输出回路提供合适的直流偏置电压。（ ）
乙类状态的导通角小于90°。（ ）
丙类谐振功放产生的集电极尖顶余弦脉冲电流只和导通角有关。（ ）
二极管峰值包络检波器适用于哪种调幅波的解调。（ ）
某单频调制的普通调幅波的最大振幅为10v，最小振幅为6v，则调幅系数ma为（ ）。
在波形上它的包络与调制信号形状完全相同的是（ ）。
调幅波的信息包含在它的（ ）。
下列关于调幅的描述，正确的是（ ）。
在二极管峰值包络检波电路中，由于检波电容放电时间过长而引起的失真是（ ）。
包络检波器是利用二极管的单向导电性及检波负载电容的充放电过程来完成检波的。（ ）
dsb调幅波中所包含的频率成分有载频、上下边频。
基极调幅电路实现的是普通调幅，也是高电平调幅。（ ）
过调制会出现失真现象。（ ）
双边带调幅的包络线可以反映调制信号波形的变化。（ ）
单边带调幅信号的波形是等幅变化的。（ ）
单边带调幅的带宽是普通调幅带宽的一半。（ ）
混频电路也属于频谱的线性搬移。（ ）
双边带调幅也可以采用包络检波方式。（ ）
变容二极管调频电路实现线性调频的条件是变容二极管的结电容变化指数为（ ）。
某调频波，其调制信号频率f=1khz，载波频率为10.7mhz，最大频偏为10khz，若调制信号的振幅不变，频率加倍，则此时调频波的频带宽度为（ ）。
鉴频描述的是（ ）。
属于频谱的非线性搬移过程的有（ ）。
单频调制时，调频波的最大频偏正比于（ ）
我国调频广播的最大频偏为75khz，当调制频率为15khz时，调频波所占的频带宽度为（ ）。
单音调制的调频波，有（ ）对边频，其调频指数的取值范围为（ ）。
调频时的频率偏移与调制信号振幅（ ），最大相移与调制信号频率（ ）。
调频有两种方法，分别称为直接调频和间接调频。（ ）
调角包括调频和调相。（ ）
调频必然调相，调相必然调频
在调频波中，频偏越大，频带也越宽。（ ）
调频波中的总功率与未调载波功率是相等的。（ ）
实现频率检波的唯一方法是将等幅的调频波变换成幅度与调频波频率变化成正比的频谱调幅波，然后再进行幅度检波。（ ）
调相频谱与调幅频谱相似。（ ）
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