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在下图电路中,当t=0时开关S断开,则t=1 s时的电流i为( )A。
A.8.63
B.6.38
C.3.68
D.4.68
A.shangxuebA.cn/images/ct_jgzjgysm_jgzjgyschoose_00225(20093)1.jpg'>
A.8.63
B.6.38
C.3.68
【参考答案】
C
解析:
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Task 1Directions: After reading the following passage, you will find 5 questions or unfinished statements, numbered 36 through 40. For each question or statement there are 4 choices marked A, B, C, and D.You should make the correct choicE.Why don't birds get lost on their long flights from one place to another? Scientists have puzzled over this question for many years. Now they're beginning to fill in the blanks.Not long ago, experiments showed that birds rely on the sun to guide them during daylight hours. But what about birds that fly by night? Tests with artificial stars have proved that certain night-flying birds are able to follow the stars in their long-distance flights.A dove had spent its lifetime in a cage and had never flown under a natural sky. Yet it showed an inborn ability to use the stars for guidancE.The bird's cage was placed under an artificial star-filled sky. The bird tried to fly in the same direction as that taken by his outdoor cousins. Any change in the position of the artificial stars caused a change in the direction of his flight.But the stars are apparently their principal means of navigation. When the stars are hidden by clouds, they apparently find their way by such landmarks as mountain ranges, coast lines, and river courses. But when it's too dark to see these, the doves circle helplessly, unable to find their way.The reason why birds don't get lost on long flights ______.A.have been known to scientists for yearsB.have only recently been discoveredC.are known by everyoneD.will probably remain a mystery
A.Why
B.
C.
D.
E.
The
F.
A.have
G.have
H.are
I.will
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Task 2Directions: This task is the same as Task 1. The 5 questions or unfinished statements are numbered 41 through 45.One silly question I simply can't stand is 'How do you feel?' Usually the question is asked of a man in action—a man on the walking along the street, or busily working at his desk. So what do you expect him to say? He'll probably say, 'Fine, I'm all right', but you've put a bug in his ear—maybe now he's not surE.If you are a good friend, you may have seen something in his face, or his walk, that he overlooked that morning. It starts him worrying a littlE.Every question has its time and placE.It's perfectly acceptable, for instance, to ask 'How do you feel?' if you are visiting a close friend in the hospital. When George Bernard Shaw, the famous writer of plays was in his eighties, someone asked him 'How do you feel?' Shaw put him in his placE.'When you reach my age', he said, 'either you feel all right or you are dead'.According to the writer, greetings such as 'How do you feel?A.show one's consideration for othersB.are a good way to make friendsC.are proper to ask a man in actionD.generally make one feel uneasy
A.One
B.
C.
According
D.show
E.are
F.are
G.generally
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