填空：John is my oldest friend.We met each other when I began t

填空：John is my oldest friend.We met each other when I began the ( )grade in the primary school.

John is my oldest friend.We met each other when I began the ( first)grade in the primary school.
翻译：约翰是我最好的朋友,自从我上小学一年级,我们认识了
再问： 这是一道选择题：A.first B. one C.two 我女儿的题，实在不会做，能讲讲理由吗？谢谢！
再答： 应该选：C the first grade 一年级 =Grade One
再问： 应该选A吧，谢谢您了！
再答： 是的。打错了选A