在and 后面逗号的作用

Question

the guest had,of course ,realized this from the moment bessie opened the door for them and ，long before the final catastrophe, had had a difficult time trying to conceal their amusement.
请问在这句句中and 后面的逗号是什么作用？为什么要加在and后面呢？请详细说明举例一下?还有of course前后为何也要家逗号呢？

Answer 1

照语法说,逗号可以出现在任何位置作为插入语,这里就是这种用法,而且不一定在and后面,可以在很多部分后面.
而插入与也只是补充说明或没有意义而只是调节语气的作用.
这里的of course就是后一种作用

Answer 2

，long before the final catastrophe, 这段是插入语
and 是连接 had had a difficult …… 这句的

of course 一个道理
He, of course, is a policeman
当然了，他是一个警察本回答被提问者采纳

Answer 3

同位语