In the United States, bus travel doesn't cost much as train travel, ________?

1. A.
   don't they
2. B.
   does it
3. C.
   do they
4. D.
   doesn't it

17..In the United States, bus travel doesn't cost much as train travel, 　　?

18.

.In the United States, bus travel doesn't cost much as train travel, 　　　　　　?

A.don't they 　           B.does it             C.do they 　　D.doesn't it

.In the United States, bus travel doesn't cost much as train travel, 　　?

A .don't they 　  B. does it          C. do they 　　    D. doesn't it

17..In the United States, bus travel doesn't cost much as train travel, 　　?
18.