接地是消除静电危害的最简单的办法,它属于()。
A、工艺控制法
B、中和法
C、泄漏法
参考答案:C
111. Trees are cut down merely for fuel and wildlife is killed simply for food. It is time to ____ an end to waste.
A.call off
B.call for
C.call in
D.call on
中性耐火材料以()氧化铬或()为主要成分。