That's where you're just asked over a period of time, how often you eat this list of foods and you're given a very long list of foods.

正如同你们刚才问的,你多久吃一次这些食物,你有一个很长的食物列表

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

They say it is important to find a balance between how hard the exercise is, how long you exercise for and how often you exercise.

BBC: Can too much exercise cause a stroke?

There is no hard and fast rule about how often and how long one must engage in self-affirmation for it to work.

CNN: Boost your capacity to cope

And PGA Tour rules, combined with a long season, limited how often players could participate in tournaments outside the U.S., where Mr. Woods could rake in millions just by showing up.

WSJ: PGA Tour Feels Absence of Tiger Woods From Golf