问题
He has been collecting shells ______ three and a half years.
A:since
B:for
C:when
D:at ;
B:for
C:when
D:at ;
正确答案是：
同类题型
Please don’t enter the room, because it is .
She got up to get some sleeping pills but found there was _________ left at home.
You can watch TV ______, but you can’t watch it ______a long time.
They are_______the same size.You can take_______half of the bread
What shall we use for power when all the oil in the world has ____________?[ ]