题目

 — The mid­term examination is in a week's time. — Yes. So we must make full use of our time, and remember every minute ________． A. affects  B. earns  C. deserves  D. counts 答案：D 甲、乙两台起重机分别以v甲＝0.2 m/s和v乙＝0.4 m/s的速度匀速提升同样的物体，使物体都升高12 m，则 [　　] A．甲做的功多，甲的功率大 B．乙做的功多，乙的功率大 C．甲、乙做的功一样多，甲的功率大 D．甲、乙做的功一样多，乙的功率大