1、________the temperature falling so rapidly, we couldn't go on with the experiment.

　　A.Since　　B.For　　C.As　　D.With

　　2、The bed has been ________ in the family. It was my great-grandmother's originally.

　　A.handed out　　B.handed over　　C.handed down　　D.handed round

　　3、By the time he arrives in Bejing, we ________ here for two days.

　　A.have been staying　　B.have stayed　　C.shall stay　　D.will have stayed

　参考答案：

　　1、D　2、C　3、D