初中英语 they weren"t fight each other but were playing together

he isn"t my borther but my friend 因为这是连接表语成份.
and /but/ or 接表语成份时,就可以省略很多.
Is it an apple or banana?
That is good and sound .
they weren"t fighting each other but were playing together
这是两个谓语成份,相当于并列句,省了主语.
再问： 并列句可以省主语 还可以省什么？ 连接表语成份 还可以省什么？