按标准化对象的基本属性，标准分为技术标准、管理标准和（）
A.服务标准
B.工作标准
C.产品标准
D.图形符号标准
参考答案：B
Mrs Green wants to buy that kind of cloth because she ____ that the cloth ____very well .
A．has been told ; washes
B．is told ; is washed
C．has been told ; is washed
D．is told ; is washed
如何查看过去的登入记录？（）
A.last
B.vi/var/log/wtmp
C.who
D.tail/var/log/wmtp
