你跳向空中后,总是会落回地面。这是因为一种叫做地心引力的力把你拉向地面。地心引力也使我们有了重量。虽然身体的重量使你往下掉,但你的肌肉可以给你一个向上的力。要做到这一点,肌肉提供的力就要比地心引力大。你能跳多高取决于你的身高以及肌肉的强壮度。 After you jump into the air, you will always fall back to the ground. This is because a force called gravity pulls you to the ground. Gravity also gives us weight. Although the weight of the body to make you fall off, but your muscles can give you an upward force. To do this, the muscles will provide more force than the gravity. How much you can jump depends on your height and muscle strength.