（）都是矿井重大灾害事故的特征之一。
A、突发性
B、规律性
C、灾难性
D、破坏性
参考答案：A, C, D
—According to my grandma, it is a good idea to eat chicken soup when you have a cold.
—_____, scientists agree with her.[ ]
A. Sooner or later
B. Once in a while
C. To be exact
D. Believe it or not
计算容车数时，小数点后不足一辆的，应当（）。
A.四舍五进
B.舍去
C.保留一位
D.进整
