Have you noticed that whatever sport you're trying to learn, some earnest person is always telling you to keep your knees bent?

Have you noticed that whatever sport you're trying to learn, some earnest person is always telling you to keep your knees bent?

你有没有注意到，不管你想学什么运动，总有一些认真的人告诉你要保持膝盖弯曲?

-- Dave Barry 戴夫-巴里