管径小于或等于100mm的镀锌钢管应采用(),被破坏的镀锌层表面及外露部分应做防腐处理。
A.法兰连接
B.卡套式连接
C.螺纹连接
D.热熔连接
参考答案:C
—What's the population of China?
— . [ ]
A. They are many
B. It's many
C. It's small
D. It's large
卸车时车辆与堆放物有一定的距离即可,没有规定的要求。