若你觉得作得很辛苦，练习三、四回也就够了。

If you find it trying, three or four times is sufficient.

youdao

一天练习三、四回，每一个只需一分钟左右就够了。

Three or four practice periods, each to last a minute or so, will be enough.

youdao

建议你练习三、四次就够了，若要发挥最大的效益，即使心生排斥，也至少练习三次。

Three of four specific practice periods are recommended, and no less than three are required for maximum benefit, even if you experienec resistance.

youdao

And this exercise of being able to work In these three different modes, economic intuition, graphs, and kind of nerdy high school math is a lot of what we want to get you used to as Economic Majors, just to be able to translate easily between those.

这个练习可以用,三种不同的方法解决,即,经济直觉,图表,和一些讨厌的高中数学,希望经济学专业的同学能掌握这些方法,对于这些方法能够随手拈来

耶鲁公开课 - 博弈论课程节选

And we do two to three concerts per year. We have two rehearsals a week.

我们每年举行二到三次音乐会。每周练习两次。

积极参与俱乐部活动 - SpeakingMax英语口语达人

We practice six days a week, usually, you know, three to four hours a day,

通常我们每周练习六天，你知道，每天三到四个小时，

赛艇项目很流行 - SpeakingMax英语口语达人