________ Switzerland is very small, ________ it is the land of watch and it is very rich．

1. A.
   Though; but
2. B.
   Because; so
3. C.
   Because;/
4. D.
   Though;/

_______ Switzerland is very small, ________ it is the land of watch and it is very rich．

A． Though; but         B． Because; so          C． Because; /            D． Though; /