main axis的用法和样例：
例句
- The main stem and fruiting branches of determinant types remain relatively short.
有限生长类型的主茎和果枝仍然较短。 - Subsequent growth of some of the axillaries results in first-order branching of the main stem.
一些腋芽继续生长形成主茎的第一级分枝。 - The wheel is revolving about its axis.
轮子在轴上转动。 - By the time the main bout came on.
这时，压轴赛上场了。
