______ the satellite launch drawing near, the research workers put their hearts to the test and always stayed up late.

1. A.
   As
2. B.
   Because
3. C.
   With
4. D.
   While

 32．______ the satellite launch drawing near, the research workers put their hearts to the test and always stayed up late.                                     

A. As                         B. Because                        C. With                D. While

．______ the satellite launch drawing near, the research workers put their hearts to the test and always stayed up late.                                          

A. As                         B. Because                        C. With                D. While

．______ the satellite launch drawing near, the research workers put their hearts to the test and always stayed up late.