they          
pronoun uk/ðeɪ/ us/ðeɪ/
A1 (作主语)他们,她们,它们
used as the subject of a verb to refer to people, animals, or things already mentioned or, more generally, to a group of people not clearly described
  I've known the Browns for a long time. They're very nice people. 我认识布朗一家已经很久了。他们都很友善。 
 Where are my glasses? They were on the table a minute ago. 我的眼镜哪儿去了?刚才还在桌子上。 
 They (= people who know) say things will be better in the new year. 他们说新的一年里情况会好转的。 
 B1 (用于代替 he 或 she)他/她
used to avoid saying "he or she"
  "There's someone on the phone for you." "What do they want?" “有人给你打电话。”“他/她有什么事?” 
 - More examples
 - My parents live down in Florida, but they come up to Chicago every summer.
 - "Thank you for the flowers." "It's all right. I thought they might cheer you up."
 - An ambulance crew was called to his home, but he was dead by the time they arrived.
 - Most children in the UK remain in full-time education until they are at least 16 years old.
 - Oil and water don't mix. Even if you shake them together they separate into two layers.