U-boats
(U-boat 的复数) n. 潜水艇
🧩 词语组成解析
n. 船艇；船（boat的复数）
🗣️ 情景例句
Oh, it's so good to see you!
噢 看到你真是太好了。
What do you do in your spare time?
闲暇时，你干些什么？
It is no use learning without thinking.
学而不思则惘。