There is a pen and a book in my bag.

There is a pen and a book in my bag.
是不是be动词只要跟后面跟的第一个匹配就可以了,
我问别人有人说分多种情况来说
不知该相信哪一位了。
如果是What are these?
是不是就应该是They are a pen and a pencil.