Sources of infection
[医] 传染源
🧩 词语组成解析
n. 输入源；发起者；来源（source的复数）
of
[əv]
prep. 关于;属于…的;由…制成;
aux. 助动词 [非标准用语、方言] =have [主用于虚拟语气];
infection
[in'fekʃən]
n. <医>传染，感染;传染病，染毒物;影响;
🗣️ 情景例句
I owe you an apology for what I did last night.
我应该为昨天晚上的事向你道歉。
I got home, feeling very tired.
我到家时都累死了[分词作状语]
But even when such refinements are not available, there is plenty to keep you occupied.
即使没有这些消遣条件，也总是有事可做。