Question

—Sam, come downstairs, please. I need your help.
—Sorry，mum. I        on the phone..

A．am talking

B．talked

C．was talking

D．have talked

Answer 1

A

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。