什么是料线？
参考答案：
料线是指高炉冶炼过程中，料面下降过程中开始加料的位置。
Teenagers are often treated like _____bigger children, but they are old enough to be
independent.
A．slightly
B．lightly
C．extremely
D．obviously
下列说法错误的是（ ）。
A． System
B． Object
C． Class
D． Thread
