问题
Is this the piano _______ yourfamiloy for over eighty years
A:once
B:when
C:while
D:as
B:when
C:while
D:as
正确答案是：
同类题型
How is your teacher today—________
It’s silly _______ you not to forgive others for theirmistakes.
They ________the train until it disappeared in the distance.[ ]
Einstein’s Theory of Relativity is so ________thatmost of us can not understand it.
Look at the sign, Sir. We don’t permit ________ in the hall.