问题
While watching television, ________.
A:the doorbell rang
B:the doorbell rings
C:we heard the doorbell ring
D:we heard the doorbell rings
B:the doorbell rings
C:we heard the doorbell ring
D:we heard the doorbell rings
正确答案是：
同类题型
That is the first time that I _____ at the meeting
Ronaldo was ______ to win the 100－meter hurdle race, but he fell to the ground andmissed the chance.
_____ with so much trouble,I am afraid, they will fail to complete the task on time [ ]
I’m looking for a place________trees grow in water．
How much _____ the elephant ______—Perhaps the ______ of it is 2 tons.