grader
n.
分类机,分级机
One that grades, especially:
特指分类者：
One who grades students' work.
阅卷评分者：给学生作业判分的人
A piece of heavy equipment used to level or smooth road or other surfaces to the desired gradient.
压路机：用来平整道路或其它表面以达到预期的坡度的一种重型设备
A student in a specified class in an elementary or high school. Often used in combination:
…年级学生：小学或高中某个班级的学生,常用于复合词：
tenth graders.
十年级学生