问题
选择题
Not until his mother came back_______.
A．he began to do his homework
B．had he began to do his homework
C．he had begun to do his homework
D．did he begin to do his homework
答案
答案：D
题目分析：考查倒装句：not until放在句首的时候，主句用部分倒装，答案在BD里面选择，句意：直到他妈妈回来，他才开始做作业。可知是妈妈回来后，他做作业，不是过去的过去的动作。选D。