如图甲所示,变压器原、副线圈的匝数比为3∶1,L1、L2、L3、L4为四只规格均

题型:选择题

问题:

如图甲所示,变压器原、副线圈的匝数比为3∶1,L1、L2、L3、L4为四只规格均为“9V,6W”的相同灯泡,各电表均为理想交流电表,输入端交变电压u的图象如图乙所示.则以下说法中正确的是

A.电压表的示数为36V

B.电流表的示数为2A

C.四只灯泡均能正常发光

D.变压器副线圈中的交变电流的频率为100

考点:正弦式交变电流
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We need to do it, ______?              [ ]

A. needn't we            

B. need we      

C. do we                  

D. don’t we

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建国以后我国的城市化进程历经曲折。20世纪50年代城市数量增长较快,60年代前期我国城市数量减少,60年代中后期和70年代城市发展处于停滞、徘徊状态,造成这种状况的原因是

①西方国家的孤立和封锁   ②经济建设盲目冒进的后果

③长时间社会动荡的影响   ④国家对工业建设重视不足

A.①②③④

B.①②③

C.①④

D.②③

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红十字事业的特点有哪些?

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When Dave was eighteen, he bought a secondhand car for 200 so that he could travel to and from work more (1) than by bus. It worked quite well for a few years, but then it got so old, and it was costing him (2) much in repairs that he decided that he had better (3) it.

He asked among his friends to see if anyone was particularly (4) to buy a cheap car, but they all knew that it was falling to pieces, so (5) of them had any desire to buy it. Dave’s friend Sam saw that he was (6) when they met one evening, and said, "What’s (7) , Dave"

Dave told him, and Sam answered, "Well, what about advertising it in the paper You may (8) more for it that way than the cost of the advertisement!" Thinking that Sam’s (9) was sensible, he put an advertisement in an evening paper, which read "For sale: small car, (10) very little petrol, only two owners. Bargain at 50. " For two days after the advertisement first appeared, there was no (11) . But then on Saturday evening he had an enquiry. A man rang up and said he would like to (12) him about the car. "All right, " Dave said, feeling happy. He asked the man whether ten o’clock the next morning would be (13) or not. "Fine, " the man said, "and I’ll (14) my wife. We intend to go for a ride in it to (15) it. "

The next morning, at a quarter to ten, Dave parked the car in the square outside his front door, (16) to wait there for the people who had (17) his advertisement. Even Dave had to (18) that the car really looked like a wreck. Then, soon after he had got the car as clean (19) it could be, a police car stopped just behind him and a policeman got out. He looked at Dave’s car and then said, "Have you reported this (20) to us yet, sir\

5()

A. some

B. neither

C. none

D. most

题型:选择题

对企业的宏观环境进行战略分析时,其中的社会环境包括( )。

A.社会文化

B.就业程度

C.国民收入状况

D.社会习俗

E.人口统计特征

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