in another word ,in other words 区别

问题描述:

in another word ,in other words 区别
He does not feel good,( ),he is ill.
A.in other words
B.in another word
we choose A.can we choose
两个都是 换句话说 的意思,为什么选项里只能选A?难道是前者更常用?

in other words是换句话说的意思,in another word 是另外一种说法的意思,从意思上看不出区别,但已经约定俗成了,如果表达的前面刚说的东西就用 in other words