两个英语句子小问题~（英盲求解）语法书上有两个主动变被动的句子：1.Theyvisitedthecitytwoyearsago.Thecitywasvisitedbythemtwoyearsago.2.Wheredidyoumakethem?Whereweretheymadebyyou.为什么两句的被

Question

两个英语句子小问题~（英盲求解）
语法书上有两个主动变被动的句子：
1.They visited the city two years ago.
The city was visited by them two years ago.
2.Where did you make them?
Where were they made by you.
为什么两句的被动一个是was一个是were?

Answer 1

第一个主语The city是单数
第二个主语they是复数