the morning show man for WGN,was the pilot of one of the planes and had been killed.

问题描述:

the morning show man for WGN,was the pilot of one of the planes and had been killed.
为什么was 前面要加一个逗号啊 是什么语法啊

原句是“What made the story hit close to home was that Bob Collins,the morning show man for WGN,was the pilot of one of the planes and had been killed.”
解释是“这个消息之所以会让人觉得震惊是因为其中一个飞行员死了,而他就是WGN的晨间播音员,鲍勃.克林斯.”
在这里the morning show man for WGN是插入语,解释之前的Bob Collions的身份的,而插入语在句中,一般是要用逗号和句子其他成分隔开的,所有将两个逗号之间的成分去掉也是一个完整的句子,即What made the story hit close to home was that Bob Collins was the pilot of one of the planes and had been killed.