【单选题】—Jane, did you finish your homework on time yesterday? —No, 1 didn't ________on time. By the time I finished it, all my classmates ________ . [ ]
A.
finish it; handed it in
B.
finish it; had handed it in
D.
make it; had handed it in
【单选题】朱建华等提出了氧化还原分离铕液膜法,可自钐、铕、钆混合稀土中分离到纯度( )%的铕,回收率84.7%。
【单选题】主动分离式拉伸单个拉伸动作持续时间是()
【单选题】以下属于主动分离式拉伸单个拉伸动作持续时间的是:
【单选题】设有如下变量声明 Dim time1 As Date, 为变量 time1 正确赋值的表达式是 _________ 。