用于表示均数抽样误差大小的统计指标是（）。
A.方差
B.标准差
C.标准误
D.变异系数
E.离均差平方和
参考答案：C
Cindy is from America, but she can __________ Chinese.
A．find B．join C．speak
Correct. 改错。
( ) 1. Nice to meeting you.
A B C
( ) 2. He is a new boy on school.
( ) 3. This is a glue.
( ) 4. Where are my paper.
( ) 5. It is Kims eraser.
