对可更换的低压断路器的灭弧触头，如磨损厚度为原来的（）时要考虑更换。
A.1/3
B.1/4
C.1/5
D.1/6
参考答案：A
契税实行( )的幅度税率。
A．1%～3% B．3%～5%C．4%～6% D．5%～7%
---- Did you go to the reading-room or the library a moment ago?
------______
A．Neither
B．No, I didn’t
C．Yes, I did
D．You are right
