—Sam, e downstairs, please. I need your help.
—Sorry,mum. I on the phone..
A. am talking
B. talked
C. was talking
D. have talked
网友回答
(答案→)A. am talking
B. talked
C. was talking
D. have talked
解析:难度适中,考查现在进行时,Sam不能去帮他妈妈,他正在谈电话,答案选A,B是一般过去时,C是过去进行时,D是现在完成时。