下列属于精煤密度范围的是（）
A、1.2-1.7g/m3
B、1.5-1.8g/m3
C、1.8-4g/m3
D、﹥4g/m3
参考答案：A
_____ from the top of the building when the policeman pointed the gun at him.[ ]
A. Jumped down the robber
B. Jumped the robber down
C. Down jumped the robber
D. Down the robber jumped
二部定价法
