石门揭煤：石门自底（顶）板岩柱穿过煤层进入顶（底）板的全部作业过程。
参考答案：对
Let's go to the store which is selling last season's clothes ______. [ ]
A. at a discount
B. in cash
C. at a price
D. for sale
建筑物的耗热量仅指通过围护结构由室内传到室外的热量。
