graders FREQ #22595 分级机 分类机 …年级学生 [建] 平地机（grader的复数） 释义与例句 n. 1. plural of grader 相关短语 seventh grader 七年级生 third graders reserve graders first graders second graders fourth graders fifth graders sixth graders seventh graders eighth graders ninth graders tenth graders eleventh graders twelfth graders thirteenth graders