控制测量的精度应以( )衡量。
A．最大误差
B．中误差
C．极限误差
D．最小误差
参考答案：B
(2012·安徽)—I love the Internet.I've come to know many friends on the Net.
—________.Few of them would become your real friends.
A．That's for sure
B．It's not the case
C．I couldn't agree more
D．I'm pleased to know that
青春期应注意均衡营养，特别要注意摄取哪种物质（ ）
A．淀粉
B．脂肪
C．蛋白质
D．维生素
