During the day we work and play and at night we sleep．Our bodies rest while we sleep．In the morning we are ready to work and play again．It is while we are asleep that our bodies grow most．When children feel tired and angry，they usually need more sleep．We can get our lessons better，and we feel better，too，when we have had plenty of rest．Boys and girls，eight or nine years old，need ten hours of sleep every night．Our bodies need plenty of air when we sleep．If we do not get enough fresh air we wake up feeling tired．While in bed we must not cover our heads．If we do，our lungs（肺）will not get enough flesh air．If we open our windows at night we can have plenty of flesh air．Cool air is better than warm air．Boys and gifts must get plenty of sleep if they want to grow and be strong．

（    ）1．Our bodies grow most while we are ________．

    A．eating                  B．playing                 C．sleeping          D．exercising

（    ）2．Which is the best air for us? __________air．

    A．Hot                     B．Cool                    C．Warm             D．Dry

（    ）3．What often makes us feel tired in the morning?

    A．Too much air．                                       B．Not enough fresh air．

    C．Too much cold air．                                   D．Too much sleep．

（    ）4．How call you get plenty of flesh air at night? You can __________．

    A．open your windows                                 B．not sleep in bed

    C．sleep ten hours                                          D．go to bed late

（    ）5．The writer is trying to tell boys and girls _________．

    A．to get their lessons better                          B．not to cover their heads

    C．how to go to bed                                       D．to get plenty of sleep