They ____________ in the river when it _________

试题详情及答案解析

They ____________ in the river when it __________ to rain.

A．were swimming; began

B．swam; was beginning

C．swam; began

D．were swimming; was beginning

答案：A

试题分析：句意:他们正在河里游泳，这时下雨了。were swimming 是过去进行时；swam 是过去式；began 开始。句中的when意思是正在这时，第一个空用过去进行时，表示当时正在游泳；第二个空用一般过去时态，表示过去发生的事情。故选A。
考点：考查动词时态。