完型填空：At different times in a man's life his food has d__1__ effects (影响) on his body.
Among children,food is quickly changed to the power to r__2__ and play games.Most of a young man's food is spent in growing t__3__; we grow upwards only during the furst twenty years of our lives,not later.Workingmen get their strong bodies f__4__ their food.Office workers beat well and s__5__ for a long time.
Many older people try to work much and walk o__6__.
That is when food c__7__ quickly to flat.