Epicyclic irain
[機] 周轉齒輪系
?? 詞語組成解析
a. [數]周轉圓的,[天] 本輪的
??? 情景例句
I hope to be able to join the school band.
我想加入學校的樂隊。
We tried in vain to make him change his mind.
我們試圖使他改變他的主意，但白費力氣。
I have quite a lot of homework to do.
我有很多家庭作業要做。