所以可以选用其中一个就行了. 或者,例如口语中就不是很严格) 2. They often help one another. (each other 一般用于两个人之间,不严格时也用于三个人以上“互相”,都表示“经常”1. They often help each other.或者:They frequently help one another.(one another 一般用于三个人以上“互相”) often 和 frequently是同义词:They frequently help each other