Each of them teaches only one subject.改为They ()teach()()()one subject.注意！一共有四个空要填！
问题描述：
Each of them teaches only one subject.改为They ()teach()()()one subject.
注意！一共有四个空要填！
答
all only
答
they all teach no more than one subject .注意：no more than表只有、仅的意思.