问题
选择题
While watching television, ____.
A．the doorbell rang
B．we heard the doorbell ring
C．there was someone knocking at the door
D．the doorbell was ringing
答案
答案：B
这题考查状语从句的省略式，由前面的While watching television可知省略了sb was，所以几个选项中，选主语是人的就可以了，所以B正确，句意是：当看电视时，我们听到门铃响了。选B。