It's a constant struggle to try to keep them up to par.

要使他们达到标准是一场持久战。

《柯林斯英汉双解大词典》

A: Yes, your last shipment wasn't up to par.

A：嗯，你上次送去的货没有达到标准。

youdao

Also, I found that in a lot of fields my English vocabulary wasn't up to par.

我也发现在很多领域我的英文词汇没有达到一定的水平。

youdao

but they won't be academically, kind of, up to par. They won't be up to snuff academically.

但是他们成绩上，有些，不达标。他们成绩上不行。

对于赞助入学的看法 - SpeakingMax英语口语达人

Lo and behold, their bonds would go up because people had discovered that you might be entitled to par.

你可以发现，他们的债券价格会上升因为人们,已经发现你可能有权以票面价值。

耶鲁公开课 - 金融市场课程节选

We had to wait until the performance was up to par with products in the market.

WSJ: Seoul Semiconductor's LED-Lighted Path

It is here that musicians get innovative ideas, and learn whether their playing is up to par.

CNN: STORY HIGHLIGHTS

Electric power not up to par, with companies complaining that a lot of it gets lost in transmission.

FORBES: Russia's Turn To Grow Slow