由.组成用英文怎么说?

consist of
be made up of
be composed of
三种都可以：
OUr class consists of 50 students.
OUr class is made up of 50 students.
Our class is composed of 50 students.
再问： be made up from呢?是不是一样的意思？
再答： be made up后接of，不接from。 最起码在高中范围，是没有from这种形式的。