问题描述：
一定要给排除每个选项的具体原因啊
while watching tv,_
a the dooebell rang
b the doorbell rings
c we heard the doorbell ring
d we hear the doorbell rings
while watching tv,_
a the dooebell rang
b the doorbell rings
c we heard the doorbell ring
d we hear the doorbell rings
问题解答：
我来补答展开全文阅读