英语啊,改错,分不是问题,急死了!

英语啊,改错,分不是问题,急死了!
Flea(跳蚤)trainers have observed a strange habits of fleas.Fleas are trained by putting it in a box with the lid on it.The fleaswill jump and hit the lid of the box over and over again.As you watch them jump and hit the lid,something very interesting become obvious.The fleas continue to jump,so they are no longer jumping higher enough hit the lid.When you take off the lid,the fleas continue to jump,but they will not jump out of the box.What?They have been conditioned themselves to jump just that high.Once conditioned to jump just that high,they just do all they can do.Many times,people limit themselves and never reach their potential.Just as the fleas,they fail to jump high,thinking they are doing what they can do.