黄土高原地区的采矿，尤其是露天采矿是导致水土流失加剧的原因之_爱下问搜题

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问题选择题

黄土高原地区的采矿，尤其是露天采矿是导致水土流失加剧的原因之一，所开采的矿产主要是[ ]

A．有色金属

B．石油

C．煤炭

D．铁矿

答案

答案：C

选择题

— We are going to have hiking trip to the Hengshui Lake. Would you like to join us?
— _____.

A. Yes, it's very kind of you
B. Of course not. I have no idea
C. Oh, that sounds unbelievable
D. I'd love to, but I have a meeting today

多项选择题

焊接冷裂纹试验方法中碳含量愈高（）。

A、钢材硬倾向愈大

B、易产生冷裂纹

C、易产生断裂