These changes will cost quite a lot , ______ they will save us money in the long run.

A. so                          B. but                               C. or                                D. for

These changes may cost quite a lot, _____ they will save us money in the long run.

These changes may cost quite a lot, _____ they will save us money in the long run.

  A. so　　              B. and            C. for                 D. but

These changes may cost quite a lot, _____ they will save us money in the long run.

1. A.
   so　　
2. B.
   and
3. C.
   for
4. D.
   but

These changes will cost quite a lot，        they will save us money in the long run．   

    A．so             B.  and            C．but          D．for  

These changes will cost quite a lot,　　　 they will save us money in the long run.　

A.so　　　　　　 B. and　　　　 C.but　　　　 D.for