You need about twenty minutes of exercise three times a week.

问题描述:

You need about twenty minutes of exercise three times a week.

你需要每周3次,每次20分钟左右的锻炼.

你需要每周做3次运动,每次20分钟。

同意大侠的版本.

你需要每周进行3次,每次大约20分钟的锻炼

你一周需要三次大约20分钟的锻炼