解析几句英文句子 语法 急

题目

解析几句英文句子 语法 急
1：I haven't read a book since graduating from hihg school.为什么graduate要用ing?
2：The cook was cutting up the meat in order to make 馄饨 in the kitchen.为什么cut用ing?
3：I want to speak to the person who is responsible for the sale of this of car.这里的who为什么不可以用which

答案

1：这里的since是介词,介词后面加动词的ing形式
2：was是be动词,后面加动词的ing形式
3：这是定语从句,which只能指代物,但是这里是person,是人,所以该用 who