My mother was cooking while Ithe radio.A listened toB have listened toC was listening to

问题补充：

My mother was cooking while Ithe radio.

A、listened to

B、have listened to

C、was listening to

答案：

解析：句意：当我正在听收音机时，我的母亲正在做饭。While引导时间状语从句时，强调动作的同时发生，本题主句为过去进行时态，故从句中也是过去进行时态。选C。