I'm sure I've got a low mark.

我的法语成绩肯定很低。

Sorry you got a low mark in your homework, but to be honest, it was bog-standard.

很抱歉你的家庭作业分数很低，但说实话这很平常。

Like either you pass or you fail, either you get high marks or low marks but that's the motivation.

不是合格就是不合格，不是高分就是低分，但我认为这就是动力。

I hate them. I'm sure I've got a low mark.

我恨他们。我确定我的分数很低。

These trestles at the low tide mark, twice a day no matter what the weather is.

这些栈桥位于退潮标志处，无论天气如何， 每天两次。

New U.S. sanctions on Russia were set to take effect today, as Russia's ruble slipped to its lowest mark in two years.

美对俄新制裁今天生效，卢布跌至两年内最低点。