有读者问这样一道填空题：
(1)There are two windows in the room. They_________face south.
请问应填 both 还是 each? 或是两者皆可以选？
这里既可以填 both，亦可以填 each。但二者的含义有所不同。 both 意指“两个都”，each 意指“两个中的每一个都。”再如：
(2)As they had both worked hard, they each received a bonus.
但按常理而言，句（1）似乎用 both 的情况较多。
