The word “conservation” has a thrifty meaning. To conserve is to save and protect, to leave what we ourselves enjoy in such a good condition that other s may also share the enjoyment. Our forefathers had no idea that human population would increase faster than the supplies of raw materials: most of them, even until very recently, had the foolish ideas that the treasures were “limitless” and could “last forever”. Most of the citizens of earlier generations knew little or nothing about the complicated and delicate system that runs all through nature, and which means that, as in a living body, an unhealthy condition of one part will sooner or later be harmful to others.
Fifty years ago, nature study was not part of school work: scientific forestry was a new idea; wood was still cheap because it could be brought in any quantity from distant woodlands; soil destruction and river floods were not national problems; nobody had yet studied long-term climate cycles in relation to proper land use; even the word “conservation” had nothing of the meaning that it has for us today.
For the sake of ourselves and those who will come after us, we must now set about correcting the mistakes of our forefathers .Conservation should be made part of everybody’s daily life. To know about the water table in ground is jus as important to us as knowledge of the basic math formulas. We need to know why all watersheds need the protection of planet life and why the running, current of streams and rivers must the duly of planting trees as well as of cutting them. We need to know the importance of big, grown trees, because living space for most man’s fellow creatures on this planet is figured not only in square measures of surface but also in cubic volume above the earth. In a word, it should be our goal to restore as much as the original beautify of nature as we can.
68. The author’s attitude towards the use of natural resources is ____
A. Positive B. uninterested C. optimistic D. critical
69. According to the author, the greatest mistake of our forefathers was that ______
A. They dad no idea about scientific forestry
B. They dad littler or no sense of environment protection
C. They were not awore of the importance of nature study
D. They dad no idea of how to make good of raw materials
70. To avoid repeating, the mistakes of our forefathers, the author suggests that _____
A. We plant more trees
B. Natural sciences he taught to everybody
C. Environmental education be given to everybody
D. We return to nature
71. How can you understand the underlined sentence in the lat paragraph?
A. Our living space on the hearth is getting smaller and smaller.
B. Our living space should be measured in cubic volume.
C. We need to take some measures to protect space.
D. We must preserve good living condition for both birds and animals.