main bearings的用法和样例：
例句
- If all the main bearings are quite loose, a great deal more noise will be evident and the frequency will increase.
如果所有的主轴承都很松动的话，大量的噪音就会很明显而且频率会增加。 - The front cover exactly matches this shape and also has a raised circular area that fits into a matching countersunk area of the block in front of the main bearing.
封面完全匹配这个形状和也提出了圆形区域，可以成为一个匹配埋头面积块前面的主轴承。
