Exocycloida
外环形棘皮目
🗣️ 情景例句
A cookie can't hurt, though.
但一片小甜饼不要紧。
Does it make any difference to you whether we have our lesson at two o'clock or at three o'clock?
我们在两点上课还是在三点上课，你觉得有关系吗？
Is it very cold in winter?
冬季的天气很冷吗？