答案:B
某县自来水收费是这样规定的:每户每月用水在12吨以内(含12吨)按0.8元一吨收费,超过12吨的,其超出部分按2.8元收费.某户五月份用水25吨,应交多少元水费?
The real-name policy for train tickets has been applied to all trains since January 1,2012 in China, ______ I think will make it easy for people to get tickets.
A.which
B.when
C.what
D.where