come in first为什么不加the

come in first为什么不加the this is our first day in school为什么first不加the first prize前为什么不加the What grade are you in?I'm in first grade,first前为什么不加the呢? 八年级英语书p57“He won first prize in his group.” first 前为什么不加the work must come first中come为啥不加s He won first prize 为什么不加the mary was the first in the exam为什么这里要在first前加the呢 In came the first ( )(run),come on He come first in the competition Did Tom come first in the race won first prize in his group 是什么意思? 什么时候 first（序数词） 前可以不加the