[填空题]It can be easier to change our diet a lot than to change it a little.

[填空题]It can be easier to change our diet a lot than to change it a little.

[单项选择]Normally a well-mixed diet can supply the vitamins necessary for a healthy body.
A. 正常情况下如果饮食搭配合理，就可提供维持人体健康必需的各种维生索。
B. 健康人体内的维生素都是由一般的搭配合理的饮食提供的。
C. 一般的搭配合理的饮食都可保证对人体健康所需的各种维生素的供给。
D. 一般的搭配合理的饮食和充足的维生素供应是维护身体健康必需的。

[简答题]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.