1.The objective of the optimal economic operation of power systems is _____.
A.to minimize the total production cost
B.to maintain frequency constant
C.to maintain voltages constant
D.to ensure balance between generation and load
2.The electric machine that operates at speeds above synchronous speed works in _____ region.
3.( ) is used as coolant in light-water reactors.
4.The toy boat turned over and sank to the (_______) of the pool.
5.How much a man can earn depends (_______) his skills.
6.Finally, the teacher realized that the girl was crying ____.
A.because what he had said
B.because that he had said
C.because of what he had said
D.because of that he had said
7.The generator voltages are usually stepped up to the transmission voltage level by _____.
8.We have come to a critical moment. You must take immediate (_______) .
9.It is generally considered unwise to give a child ____ he or she wants.
10.Can you come over for dinner with us? ----- (_______)
A.I'd like to but I have a meeting tonight
B.It doesn't matter
C.No, I don't like
D.Oh, that sounds well
11.Thank you ever so much for the book you gave me.
--- (_______) .
B.I’m glad you like it
C.Yes, it is good
D.No, it’s not so good
12.She is an easy-going girl. _________ you meet her, she will smile to you.
13.The new English book I bought yesterday (_______) me almost twenty yuan.
14.Let's go by car. It's _______.
A.cheap a lot
15.Image clarity on a computer screen is measured with _____.
16.The Buck(降压式变换器) is a ( ) converter.
17.When an induction motor with 10 poles is supplied by 50Hz three-phase ac power source, the synchronous revolutions per minute is _____. (Synchronous r/min = 120 f/p)
18.——Have a good rest ; you need to ___your energy for the football match this afternoon .——Thanks a lot .
19.Her eyes were filled (_______) tears.
In a coal-fired power plant, an electrostatic precipitator is used to remove _____ from the combustion gases.
D. water vapour
21.May I have a look at your photo album?
--- (_______) .
A.Yes, you have
B.It’s very interesting
C.This is my girl friend
D.Yes, of course
22.They have lessons every day (_______) Saturday.
23.I’ll make every (_______) to help you.
24.Most desktop computers use a separate _____ as a display device, where notebook computers use a flat panel LCD screen (liquid crystal display screen) that attached to the system unit.
25.The unit of logarithm of the magnitude of a transfer function is _____.
A.radians per second
26.The teacher advised Joe to___before deciding to quit school.
27.The red rose is her (_______) .
28.Be sure to (_______) your work at the end of the exam.
D.catch sight of
29.-________ you ________ free tomorrow?– No. I ________ free the day after tomorrow.
B.Are;going to be;will
C.Are;going to;will be
D.Are;going to be;will be
30.It was on the beach (_______) Miss White found the cat lying dead.
31.Living in the central Australian desert has its problems, ___getting water is not the least.
32.She would make a teacher far (_______) to the average.
33.I have no doubt (_______) he will overcome all his difficulties．
34.This one is not good, that one is ____.
35.When you have difficulties in translating the article, don’t (_______) to ask me.
36.As I felt so much better, my doctor (_______) me to take a holiday by the sea.
37.A computer printer is _____ device that produces computer-generated text or graphical images on paper.
D.a data processing
38.The village was (_______) two or three groups of simple houses, a church, a post office and a small general store.
39.The DC-DC converts _____ input to _____ output.
A.direct current, alternating current
B.direct current, direct current
C.alternating current, alternating current
D.alternating current, alternating current
40.The transformer is a straightforward application of Faraday’s ______ Law.
41.Must I be home before seven?
--- (_______) .
A.No, you needn’t
B.No, you mustn’t
D.no, you won’t
42.These heavy walls expressed man's fear of the outer world and his need to find (_______) .
43.My pain___obvious the moment I entered the office, for the first man I met asked pitifully, “Are you feeling all right?”
B.could have been
D.must have been
44.The ship set out for the (_______) of the ocean depths.
45.These are all (_______) demands.
46.Charlie ________ here next month.
C.isn't going to working
47.We go to the cinema (_______) a week.
48.The story of George Washington and the cherry tree is (_______) every American school child.
49.The proposal seems quite good, but I can’t easily (_______) without all the facts.
50.—Is there anything I can do for you, sir?— ___.
A.Sure. Go ahead
B.No. Take your time
C.Yes. You’re welcome
D.Not now. Thanks anyway