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【单选题】
Man and Nature The balance of nature is a delicate system of checks and counterchecks. Nature has its own way of checking the life and distribution of the different organisms and helping their growth. An epidemic may be considered nature's way of checking population growth. Man in his attempt to conquer nature and to utilize it to his advantage has interfered with the balance of nature, thereby creating problems of a complex nature. Nature's ways of maintaining the balance are intricate and not easily understood and man's application of his scientific knowledge and techniques has upset this balance so much that today, being aware of the disastrous consequences, he takes measures against them. No animal or plant can live in isolation, for different organisms are parts of a vast dynamic complex of living things. As no man or community is self-sufficient, no organism can live by itself. When man interferes with the interdependence and interrelationships of the different organisms, he is, in effect, upsetting their balanced relationships and his action can have a chain reaction. If we prevent fish eggs from being deposited in a pond, we are allowing an unchecked growth of weeds. The waterfowl which feeds on tadpoles will look for alternatives, thereby tending to upset these balanced relationships. It is important that for the preservation of beauty in nature the balance of nature is maintained. Man for his own survival has to make his peace with plant and animal life, the size and distribution of which he has interfered with. It is to be noted that in every plant and animal community there is a trend towards a balance between the different species. When each successive species is of the right number to maintain a constant population, a balance between the different species is maintained and this state is referred to as the climax stage. Man is forever upsetting the balance of the climax stage. He has added to the numbers of animals and plants that are useful to him. In the process he has unwittingly helped the increase in the number of insects and vermin and as a result he has to wage a relentless war against them. If man continues to interfere with the balance of nature, it is possible that some animals and birds may soon become extinct. The indiscriminate hunting of whales has reduced the number of some species almost to the verge of extinction and international laws have been drawn up to protect them. The balance of nature is to be maintained in order to prevent soil deterioration. Human intervention has altered the established relationship between the plants of an area and the soil of that area. Animals introduced by man, sheep and goats for example, have led to widespread soil deterioration. By cutting down trees or by practising unsuitable systems of agriculture, man destroys the crumb structure of soil, thereby making it susceptible to erosion. Soil erosion results in loss of soil fertility and maintaining soil fertility is considered the biggest problem facing mankind apart from the prevention of war. The increase in world population and the growth of civilisation have been the two major factors that have led man to cut down forests on an unprecedented scale and the erosion caused by the cutting down of huge areas of forests has resulted in floods on a scale hitherto unknown. Soil erosion can whittle away soil fertility and if adequate and effective measures are not taken it can become a menacing spectre tearing at the prosperity of many countries. Pollution, in its different forms, interferes with the balance of nature. Water pollution affects nature's balance in oceans, lakes and rivers. Man-made pollution of water is due to, municipal sewage, dumping by factories and the depositing of pesticides. Solid wastes can permeate the soil and pollute lakes and rivers. Man has to adopt the philosophy of thrift by conserving natural resource
A.
Y
B.
N
C.
NG
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【判断题】在水路运输合同中,货物发运前,承运人或托运人不管是否征得对方的同总,可变更货物的到达港和收货人。()
A.
正确
B.
错误
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A.
开出并承兑商业汇票抵付前欠外单位账款
B.
以银行存款偿还前欠外单位账款
C.
联营到期,退还投资者投资
D.
将盈余公积转增资本金
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A.
D点连着销钉
B.
D点不带销钉
C.
D点不带销钉
D.
D点连着销钉
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A.
将资本公积转增资本
B.
接受投资者投资
C.
以银行存款偿还债务
D.
从银行提取现金
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A.
灰铸铁
B.
可锻铸铁
C.
球墨铸铁
D.
合金铸铁
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A.
灰口铸铁
B.
可锻铸铁
C.
球墨铸铁
D.
合金铸铁
【判断题】( )在水路运输合同中,货物发运前,承运人或托运人不管是否征得对方的同意,均不可解除运输合同。
A.
正确
B.
错误
【单选题】铸铁的牌号为 HT300 ,它表示此铸铁是( )
A.
灰铸铁
B.
可锻铸铁
C.
球墨铸铁
D.
合金铸佚
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A.
正确
B.
错误
【单选题】天车常用的HT300是表示()抗拉强度为300MPa的灰铸铁
A.
最低
B.
最高
C.
许用
D.
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