Faculative
a. 允许的, 任意的, 兼性的, 偶发的
🗣️ 情景例句
Remember to lock your door and windows when you leave the house.
出门前记得锁好门窗。
The audience stared the acrobats in great wonder.
观众以惊异的眼光注视着杂技演员。
I don't know.I've already had my holiday this year.
我不知道。今年我已度过假了。