— What would you like to ___________?
— Some water, please.[ ]
A. eat
B. drink
C. do
答案:B
抽样的方法一般有()。
A.简单随机抽样
B.系统抽样
C.分组抽样
D.分层抽样
Let's ______ ping-pong. [ ]
A. to play
B. play
C. plays
D. play to