题目

While waiting for the opportunity to get     , Henry did his best to perform his duty. A. promote   B. promoted   C. promoting   D. to promote 答案：B伏安法测电阻的接法有如图中甲、乙两种，下列说法正确的是(    )A.两种接法完全等效B.按甲图接法测得的值偏小C.若待测电阻的阻值很大，按甲图接法误差较小D.若待测电阻的阻值很小，按甲图接法误差较小