The world is a school ; I consider the world a school为什么第二句中间不加IS

The world is a school ; I consider the world a school为什么第二句中间不加IS
The world is a school ; I consider the world a school
为什么第二句中间不加IS

The world is a school ; I consider the world a school为什么第二句中间不加IS
固定句型：consider sth as sth

consider大部分时间是和as在一起的,同时有时候这个as也可以省略,所以就这样了啊