Here are two letters,Bob ______is for you and _____is for your father.

问题描述:

Here are two letters,Bob ______is for you and _____is for your father.
a one anthers b one the second c one the other d one others

c one,the other能告诉我为什么吗??题目中只提到有两封信。others表示其他的(不止一个),the second 是序数次,anothers没有这个用法