- Sam, I called you yesterday evening, but no one answered.    

- Oh, sorry. I _______ a shower at that time.   [ ]

A. took              

B. am taking          

C. take              

D. was taking

新采煤机下井运转使用（）周后，必须对所有的螺栓紧固件逐个进行重新紧固。

A、2

B、1

C、4

D、3