自由液面对GM影响值与（）成正比。
A.自由液面对其中心轴的面积惯性矩
B.液舱内液体密度
C.自由液面尺度
D.A、B和C
参考答案：D
根据句意及首字母补全在本课中出现的单词。
1. E_____ in our class can help each other.
2. In the early morning,the air is very f_____ .
3. It's a h_____ store,We can't move it.
4. We should o_____ a club to collect the paper.
5. Please b_____ your stamp collection to school.
盘车电机电流低于（）安培，才能启动主电机。
A.30
B.25
C.35
D.40
