最快速，成本最低的调查方法是：（）。
A.电话调查
B.邮寄调查
C.网上问卷调查
D.手机短信调查
参考答案：C
Tom didn't go upstairs ____ his mom cleaned up his room.[ ]
A. until
B. from
C. in
D. after
简述中共十六大提出的全面建设小康社会的奋斗目标。
