grade

来自PIE*ghredh, 走，台阶，层级，词源同ingress, aggressive.后词义通用化，年级。

grade (n.)

1510s, "degree of measurement," from French grade "grade, degree" (16c.), from Latin gradus "step, pace, gait, walk; step on a ladder or stair;" figuratively "a step, stage, degree," from gradi (past participle gressus) "to walk, step, go," from PIE *ghredh- "to walk, go" (cognates: Lithuanian gridiju "to go, wander," Old Church Slavonic gredo "to come," Old Irish in-greinn "he pursues," and second element in congress, progress, etc.). Replaced Middle English gree "step, degree in a series," from Old French grei "step," from Latin gradus.

Meaning "inclination of a road or railroad" is from 1811. Meaning "class of things having the same quality or value" is from 1807; meaning "division of a school curriculum equivalent to one year" is from 1835; that of "letter-mark indicating assessment of a student's work" is from 1886 (earlier used of numerical grades). Grade A "top quality, fit for human consumption" (originally of milk) is from a U.S. system instituted in 1912. To figuratively make the grade "be successful" is from 1912; early examples do not make clear whether the literal grade in mind was one of elevation, quality, or scholarship.

grade (v.)

1650s, "to arrange in grades," from grade (n.). Meaning "to reduce (a road, etc.) to a level or degree of inclination" is from 1835. Meaning "assign a letter mark to" is from 1931. Related: Graded; grading.

1. The boy first showed promise as an athlete in grade school.

这个男孩在上小学的时候就初次显示出成为运动员的潜力。

2. South Point College does not grade the students' work.

南点学院不对学生的作业评分。

3. It was actually used for enriching uranium to weapons-grade levels.

实际上，它是用来将铀浓缩以制造武器。

4. Simply sand them down with a fine grade of sandpaper.

只要用细砂纸把它们打磨一下即可。

5. All parts are machined from top grade, high tensile aluminium.

所有零件都是用顶级高强度铝加工而成。