单项选择题

下列选项中，( )是衡量公路网的一项主要指标，反映了公路网总体建设及其规模特性。

A.公路网长度
B.公路网密度
C.公路网面积
D.交通网密度

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Everyone of us lives and works on a small part of the earth's surface, moves in a small circle, and of these acquaintances knows only a few intimately. Of any public event that has wide effects we see at best only a phase and an aspect. This is true that the eminent insiders, who draft treaties, make laws, and issue orders, are like those who have treaties framed on them, laws promulgated to them, orders given at them. Inevitably our opinions cover a bigger space, a longer reach of time, many things, that we can directly observE.So they have to be pieced together out of what others have reported and what we can imaginE.Yet even the eyewitness does not bring back a naive picture of the scenE.For experience seems to show that he himself brings something to the scene which later he takes away from it, that oftener than not what he imagines to be the account of an event is really a transfiguration of it. Few facts in consciousness seem to be merely given. Most facts in consciousness seem to be partly madE.A report is the joint product of the knower and known, in which the role of the observer is always selective and usually creativE.The facts we see depend on where we are placed, and the habits of our eyes.The limited time and space which man occupies suggest, according to the paragraph,A.man's life is also insignificant.B.man's opinions can not be accurate at all.C.human observations in general are all but partial.D.man cannot have any opinion.

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The fridge is considered necessary. It has been so since the 1960s when packaged food list appeared with the label: 'Store in the refrigerator.'In my fridgeless fifties childhood, 1 was fed well and healthy. The milkman came every day, the grocer, the butcher (肉商), the baker, and the ice-cream man delivered two or three times each week. The Sunday meat would last until Wednesday and surplus(剩余) bread and milk became all kinds of cakes. Nothing was wasted, and we were never troubled by rotten fooD.Thirty years on food deliveries have ceased, fresh vegetables are almost unobtainable in the country.The invention of the fridge contributed comparatively little to the art of food preservation. Many well-tried techniques already existed -- natural cooling, drying, smoking, salting, sugaring, bottling...What refrigeration did promote was marketing --- marketing hardware and electricity, marketing soft drinks, marketing dead bodies of animals around the world in search of a good pricE.So most of the world's fridges are to be found, not in the tropics where they might prove useful, but in the rich countries with mild temperatures where they are climatically almost unnecessary. Every winter, millions of fridges hum away continuously, and at vast expense, busily maintaining an artificially-cooled space inside an artificially-heated house -- while outside, nature provides the desired temperature free of chargE.The fridge's effect upon the environment has been evident, while its contribution to human happiness has been not important. If you don't believe me, try it yourself, invest in a food cabinet and mm off your fridge next winter. You may not eat the hamburgers, but at least you'll get rid of that terrible hum.The statement 'In my fridgeless fifties childhood, I was fed well and healthily.' suggests thatA.the author was well-fed and healthy even without a fridge in his fifties.B.the author was not accustomed to fridges even in his fifties.C.there was no fridge in the author's home in the 1950s.D.the fridge was in its early stage of development in the 1950s.

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