There was an entire elementary school year in which my son got consistently mediocre grades in math, in English, in everything, it seemed.

有一整个学年，我儿子的成绩表现一直不上不下，数学方面如此，甚至还有英语，看起来似乎每一门课都是如此。

youdao

It also meant that the better schools could receive mediocre grades becausethey were already performing well and had little room for improvement.

同时这还意味原本更优秀的学校却只能获得平凡的等级评价，因为他们的进步空间相对小得多。

youdao

The mediocre person answers only 30% of the questions correctly admits that he has only average grades he worked on the yearbook as a proofreader and he tried out for the track team but didn't make it.

后者回答正确30%的问题,坦白学习成绩一般,给年刊做校对,尝试参加校田径运动队，但没成功。

耶鲁公开课 - 心理学导论课程节选

But blacks with good grades had fewer black friends than their mediocre peers.

ECONOMIST: Black America