仿照例句用所给的词汇造句。

例：I, do my homework, last night

       I was doing my homework last night.

A. they, have a dress rehearsal, yesterday evening

B. my grandma, visit my family, half an hour ago

C. I, travel in the south, at this time last year

D. they, build a power station, at that time

海上拖航合同的责任期间是指（）这一段时间，只有在责任期间内发生的责任事故造成的损失，有关当事人才需依据拖航合同承担赔偿责任。

A.货物装上被拖船时起至货物卸离被拖船时止

B.货物装上拖船时起至货物卸离拖船时止

C.开始连接拖缆时起至最终解开拖缆时止

D.起拖时起至拖航结束时止