—Where's your pencil?
—It's_________.
A. in the box
B. a pen
C. a pencil-box
答案:A
He had intended to do some physics homework during the play, but he soon _____ the play so much that he
forgot all about the homework. [ ]
A. busied himself enjoying
B. involved himself to enjoy
C. found himself enjoying
D. convinced himself to enjoy
对于定速泵来讲,其流量增加,扬程必然()
A、降低;
B、增加;
C、不变;
D、不确定