Vicissitudinary
a. 交替的,轮流的
🗣️ 情景例句
I have never confirmed that the Roswell base exists, but I can't deny it either.
我从没有说过拉兹威基地存在，但我也不会否认。
What did he ask you?
他问你什么？
Precautions of this sort are necessary, for it is impossible to foretell the exact nature of the difficulties which will confront the pot-holer.
作出这样的准备是必要的，因为无法预见到洞穴探险者究竟会遇到什么性质的困难。