Mr. White works as a lawyer now, but he     in a company for several years.

A．worked

B．has worked

C．had worked

D．has been working

在Word中，要移动文档中的字符，不能实现的操作是_____

A．使用工具栏

B．使用鼠标拖动

C．使用菜单命令

D．使用滚动条