在Windows环境下，工具栏中用于完成复制操作的按钮是（ ）。
A．
B．
C．
D．
参考答案：C
He has left his book here ____ so that you can read it. [ ]
A. by chance
B. by purpose
C. by accident
D. on purpose
有雇工个体工商户办理社保登记收费吗？收费标准是多少？办理时候需提供哪些资料？
