句型转换。

1. A. Because I was exhausted,I slid into bed and fell fast asleep.

    B.____I said into bed and fell fast asleep.

2.  A.  We didn't leave the station until we couldn't see the train.

     B.  We didn't leave the station until we_____ _____ ______the train.

3. A. The leaves provided the house with oxygen that was needed badly.

    B. The leaves provided the house with ______oxygen.

4.  A.  When it is seen from the top of the hill,our school looks more beautiful.

     B.  ______  _____the top of the hill,our school looks more beautiful.

5.  A. Though they had been wamed of the storm,the farmers were still working in the fields.

     B. ____ ____ ____ ____,the farmers were still working in the fields.