揭开活动盖时,在沼气池周围吸烟或使用明火,这种行为应该:()。
A.允许
B.可以
C.禁止
D.顺其自然
参考答案:C
Kangkang has learned over ________ English words for two years.
A. five thousand, eight hundreds and sixty-five
B. five thousands, eight hundred and sixty-five
C. five thousand, eight hundred and sixty-five
190型柴油机()是利用曲轴箱内飞溅起的润滑油进行润滑。
A.连杆瓦与曲轴之间
B.连杆铜套与活塞销之间
C.汽缸套与活塞之间
D.摇臂轴与衬套之间