晋城煤业集团东区主要可采煤有()。
A、3号煤
B、6号煤
C、9号煤
D、15号煤
参考答案:A, C, D
When I came inside the office, they ________ a party for the coming festival.[ ]
A. planned
B. were planning
C. plan
反粒子的质量、寿命、自旋等与粒子相同,而()与粒子异号。