煤根据平均光泽强度、煤岩成分的数量比例和组合情况划分为哪四种宏观煤岩类型？
参考答案：
光亮型、半亮型、半暗型和暗淡型
Let him show ____________ around ____________ school. [ ]
A. our, her
B. us, him
C. we, his
D. us, his
GEM的背板没有下面哪些总线？（）
A.DL3B
B.EMB
C.RPB
D.MB
