The boy was so tired that he fell asleep _______ his mother could take off his clothes.

A. before                 B. after                       C. while                  D. when

The boy was so tired that he fell asleep ______ his mother could take off his clothes．

    A．before       B．after               C．while       D．when

The boy was so tired that he fell asleep ______ his mother could take off his clothes．

1. A.
   before
2. B.
   after
3. C.
   while
4. D.
   when

The boy was so tired that he fell asleep ______ his mother could take off his clothes．

       A．before            B．after                                           C．while                D．when

 The boy was so tired that he fell asleep _______ his mother could take off his clothes.

A. before                  B. after                    C. while                 D. when

The boy was so tired that he fell asleep ______ his mother could take off his clothes．