Adults are often surprised by how well they remember something they learned as children but have never practised in the meantime. A man who has not had an opportunity to go swimming for years can   1    swim as well as ever when he gets back in the water. He can get on a bicycle after several decades and still    2    away. A mother who has not   3   the words for years can teach her daughter the poem that begins "Twinkle, twinkle, little star" or recite the story of Cinderella or Snow White.
　　One explanation is the law of over learning, which can be stated as following:   4 we have learned something, additional learning increases the   5     of time we will remember it.
　　In childhood, we usually continue to practise such skills as swimming, bicycle riding long after we have learned them. We continue to listen to and   6    ourselves of poems such as "Twinkle, twinkle, little star" and childhood tales such as Cinderella or Snow White. We not only learn but __7   .
　　The law of over learning explains why cramming (突击学习) for an examination,   8    it may result in a passing grade, is not a    9    way to learn a school course. By cramming, a student may learn the subject well enough to get by on the examination, but he is likely soon to forget almost everything he learned. A little over learning,    10   , is usually a good investment toward the future.

A．only B．still C．hardly D．even

A．move B．ride C．travel D．drive

A．showed up B．cared for C．thought about D．brought up

A．Once B．Before C．Until D．Unless

A．warm B．inform C．remind D．recall

A．recite B．research C．overlearn D．improve

A．so B．though C．if D．after

A．satisfactory B．demanding C．convenient D．swift

A．at most B．on the other hand C．by the way D．in the end