绿色环保概念将成为新世纪电梯的技术发展方向，其特点不包括（）。
A、故障率低
B、无污染
C、低噪音
D、节能
参考答案：A
-I haven't been to the Great Wall.
-If you have an opportunity ________ there, you must take it. [ ]
A. to go
B. to going
C. going
D. go
“征免”栏应填( )。
A．照章征税
B．全免
C．折半
D．征免
