When doing my homework .A. I heard the doorbell ringB. the doorbell rangC. my mother came

问题补充：

When doing my homework,.

A. I heard the doorbell ring

B. the doorbell rang

C. my mother came in

D. my mother was cooking

答案：

(答案→)A. I heard the doorbell ring

B. the doorbell rang

C. my mother came in

D. my mother was cooking

解析：考查状语从句的省略和宾语补足语：句意：当做作业的时候，我听见门铃响了。“while”后接的是现在分词短语，在句中作状语，它逻辑上的主语应该是我，不是the door，也不是my mother，又因为hear后接复合宾语时，这个复合宾语应包含一个省略to的动词不定式或现在分词短语。所以本题选A项。