－Have you seen the film Lost in Thailand?

－Oh, no. I ___ my homework all day yesterday.

A．had done

B．did

C．have done

D．was doing

下图所示实验操作错误的是 [ ]

A.用带火星的木条验满氧气

B.检查装置的气密性

C.滴管用后不洗涤直接插入滴瓶 

D.试管口塞橡皮塞