第1题: [单项选择]对重力运搬叙述不正确的是() A. 应用空场法采矿时,矿体倾角大于50°~55°,方能考虑应用重力运搬; B. 应用崩落采矿法时,矿石能沿65°~80°倾斜面借重力向下滚动; C. 采场矿石重力运搬时受矿体倾角影响很大,因此水平矿体不能采用重力运搬方式; D. 溜井中重力运搬,其倾角一般不小于55°~60°。 参考答案:C
第31题: [单项选择]All normal human beings are ______ at least to a degree they get a feeling of warmth and kinship from engaging in group activities. A. segregated B. congregational C. gregarious D. egregious 参考答案:C 答案解析:[解析] C选项gregarious(社交的,群居的)符合题意,如:gregarious bird species(群居的鸟类)。A选项segregated(被隔离开的)、B选项congregatio