填空题

How often one hears children wishing they were grown up, and old people wishing they were young again. Each age has its (11) and its pains, and the happiest person is the one who enjoys what each age gives him without wasting his time in (12) . Childhood is a time when there are few (13) to make life difficult. If a child has good parents, he is fed, looked after and loved, whatever he may do. It is (14) that he will ever again in his life be given so much without having to do anything (15) . In addition, life is always presenting new things to the child—things that have lost their interest for older people because they are too well known. But a child has his pains: he is not so free to do what he wishes to do; he is continually being told not to do things, or being punished for what he has done wrong.