碱性蓄电池,配制好的电解液应静置( ),使其澄清后使用。
查看答案
The reason for his failure is ______ he didn't work hard.
A. that
B. as
C. since
D. because
Mary is in bed with a fever and she can't hope to ______ the cold in a few days.
A. get over
B. get away
C. get off
D. get out
对于UPS电源中的逆变器,不是简单地将直流变成交流,尚需实现( )电压的自动调节。
A. 输入
B. 输出
C. 波形
D. 特定
They required that all the necessary documents ______ to the president's office before the end of this month.
A. be handed
B. must be handed
C. should hand in
D. had been handed in