膳食中缺乏水和（）会诱发或加重便秘。

A.矿物质

B.硫酸软骨素

C.维生素

D.微量元素

Our life is nothing more than our time. To kill time is therefore a form of suicide. We are shocked when we think of death, and we spare no pains, no trouble, and no expense to preserve life. But we are too often indifferent to the loss of an hour or of a day, forgetting that our life is the sum total of the days and of the hours we live. A day or an hour wasted is therefore so much life forfeited. Our life is a brief span measuring some seventy or eighty years in all. But nearly one third of this has to be spent in sleep; some years have to be spent over our meals; some in making journeys on land and voyages by sea; some in merrymaking; some in watching over the sickbeds of our nearest and dearest relatives. Now if all these years were to be reduced from the term over which our life extends, we shall find about twenty or thirty years at our disposal for active work. Whoever remembers this can never willingly waste a single moment of his life.