题目

如图14-10-5所示的电路，测电流表的内阻时，下述操作中哪些是错误的(    ) 图14-10-5A.闭合S1前R应调到最小值B．闭合S1前R应调到最大值C.闭合S2后，在调节R′时，还要改变R的阻值D．闭合S2后，在调节R′时，不能改变R的阻值 答案：BD 完形填空。        Strange things happen to time when you travel, because the earth is divided into twenty - four parts,     1   a part. You can have days   2   more or fewer than twenty - four hours, and    3   with more or fewer   than seven days.       Your ship goes into   4   time part every day if you make a five - day journey across the Atlantic   Ocean. As you go into each part, the time   5   one hour. Traveling west, you   6   your clock back;   traveling east, you let it ahead. Each day of your jou rney has   7   twenty-five or twenty-three hours.       If you travel by ship across the Pacific, you will   8   the International Date Line. This is the point   where a new day _ 9  . When you go across the line, you change your calendar one  10   day, back or   ahead. (     )  1. A. four hours (     )  2. A. between (     )  3. A. years   (     )  4. A. a different (     )  5. A. turns  (     )  6. A. take        (     )  7. A. neither     (     )  8. A. cross       (     )  9. A. lasts        (     ) 10. A. all         B. two hoursB. with    B. months   B. the same   B. changes   B. give       B. not        B. get        B. begins     B. more       C. half an hourC. for          C. seasons       C. an interesting C. has          C. put           C. either       C. catch         C. follows       C. full         D. one hour   D. at         D. weeks      D. a moving   D. makes      D. set        D. never      D. touch      D. breaks     D. less