first year与first—year有什么不同.

first year与first—year有什么不同. first-year与first year有什么不同? 求教英语高手【first-year与first year有什么区别】 first year first-year 请问：in first year 和 in the first year 有什么区别?the end-of-year与end of year有什么不同 year by year与year after year有什么区别 in the first year和at the first year first year的英文是什么意思 The first month of a year is J.J什么? the first nine days in this year有没有语法错误?