Passive air defense
un. 消极防空
🧩 词语组成解析
air
[ɛə]
n. 天空;气氛;空运;（简单易记的）曲调;
vt.& vi. 晾晒;烘干;播送;广播;
vt. 使房间通风， 透气;
🗣️ 情景例句
and a book of photos about the United States still feels right.
而一本关于美国的摄影集仍然很有前景。
I'll make it up to you.
我会赔偿的。
'I was just wondering how to spend the morning -- until I saw you.
“我正不知道怎么消磨这一上午呢，正好见到好。