Jestful
a. 詼諧的, 開玩笑的
??? 情景例句
OK. Thanks. See you later.
好 謝謝。再見。
I could swear I've been here before.
我敢發誓我曾經來過這兒。
a trough (the lowest point), a height (the vertical distance from the trough to the crest),
波谷（最低點）、浪高（從波谷到浪峰的垂直距離）