The United States Army has now determined that glare from snow does not cause s
nowblindness in troops in a snow-covered country.Rather, a man's eyes frequently find nothing to foucs on in a broad expanse of barren snow-covered terrain. So his gaze continually shifts and jumps back and forth over the entire landscape in search of tsomething to look at. Finding nothing, hour after hour, the eyes never sotp searching and the eyeballs become sore and the eye muscles ache. Nature offsets this irritation by producing more and fluid which covers the eyeball. The fluid coversthe eyeball in increasing quantity until vision blurs, then is obsured,and the result is total, even though temporary,snowblindness. Experiments led the Army to a simple method of overcoming this problem. Scouts ah
ead of a main body of troops are trained to shake snow from evergreen bushes, creating a dotted line as they cross completely snow-covered landscape,Even the scouts themselves throw lightweight , dark colored objects ahead on which they too can focus . The men following can then see something.Their gaze is arrested. Their eyes focus on a bush and having found something to see,stop scouring the snow-blanketed lanscape. By focusing their attention on one object at a time,the men can cross the snow without becoming hopelessly snowblind or lost. In this way the problem of crossing a solid white terrain is overcome. 1.To prevent headaches, watering eyes and blindness caused by the glare from snow,
dark glasses are_____. a.indispensible b.useful c.ineffective d.available 2.When the eyes are sore tears are produced to ________. a.clear the vision b.remedy snowblindness c.ease the irritation d.loosen the muscles 3.Snowblindness may be avoided by_______. a.concentrating to the solid white terrain b.searching for something to look at in snow-covered terrain c.providing the eyes with something to foucs on d.covering the eyeballs with fluid 4.The scouts shake snow from evergreen bushes in order to _______. a.bive the men behind something to see b.beautify the landscape c.warm themselves in the cold d.prevent the men behind from losing their way 5.A suitable title for this passage would be _______. a.snowblindness and how to overcome it b.natrue's cure for snowblindness c.soldiers in the snow d.snow vision 答案：CCCAA 十九 Water problems in the future will become nore intense and more complex. Our incre
asing population will tremendously increase urban wastes,primarily sewage. On the other hand, increasing demands for water will decease substantialy the amount of water available for diluting wastes. Rapidly expanding industries which involve more and more complex chemical processes will produce large volumes of liquid wastes, and many of these will contain chemicals which are noxious. To feed our rapidly expanding population, agriculture will have to be intensified. This will involve ever-increasingquantities of agricultural chemicals, From this , it is apparent that drastic steps must be taken immediately to develop corrective measures for the pollution problem. There are two ways by which this pollution problem can be dwindled. The first relat
es to the treatment of wastes to decrease their pollution hazard. This involves the processing of solid wastes \to \disposal and the treatment of liquid wastes, or efflunets,to permit the reuse of the water or minimize pollution upon final disposal. A second approach is to develop an economic use for all or a part of the wastes. Far
m manure is spread in fields as a nutrient or organic supplement . Effluents from sewage disposal plants are used in some areas both for irrigation and for the nutrients contained. Efflunets from other processing plants may also be used as a supplemental source of water. Many industries, such as meat and poultry processing plants, are currently converting former waste products into marketable byproducts. Other industries are potential eonomic uses for waste products. 1.The purpose of this passage is ______. a.to alert the reader to the dwindling water supply b.to explain industrial uses of water c.to acquaint the reader with water pollution problems d.to demostrate various measures to solve the pollution problem 2.Which of the following points is NOT INCLUDED in the passage? a.In dustrial development incudes the simplification of complex chemical processes. b.Diluting wastes needs certain amount of water c.Demands for water will go up along with the expanding population d.Intensive cultivation of land requires more and more chemicals 3.The reader can conclued that________. a.countries of the world will work together on polution problems b.byproducts from wastes lead to a more prosperous marketplace c.science is making great progress on increasing water supplies d.some industries are now ,aking economic use of wastes 4.The author gives substance to the passage through the use of _______. a.interviews with authorities in the field of water controls b.opinions and personal observations c.definitions which clarify important terms d.strong arguments and persuasions 5.The words \to \probably mean______. a.after b.during c.before d.beyond 答案:cadbc 二十 One of the qualities that most people admire in others is the willingness to admit on
e's mistakes. It is extremely hard sometimes to say a simple thing like \was wrong about that,\it is even harder to say, \was wrong , and you were right about that.\ I had an experience recently with someone admitting to me that he had made a mis
take fifteen years ago. He told me he had been the manager of a certain grocery store in the neighbourhood where I grew up, and he asked me if I remembered the egg cartons. Then he related an incident and Ibegan to remember vaguely the incident he was describing. I was about eight years old at the time, and I had gome into the store with may mo
ther to do the weekly grocery shopping. On that particular day, I must have found my way to the dairy food department where the incident tood place. There must have been a special sale on eggs that day because there was an impress
ive display of eggs indozen and half-dozen cartons. The cartons were stacked three or four feet high. I must have stopped in front of a display to admire the stacks. Just then a woman came by pushing her grocery cart and knocked off the stacks of cartons. For some reason, I decided it was up to me to put the display back together, so I want to work. The manager heard the moise and came rushing over to see what had happened. W
hen he appeared, I was on my knees inspecting some of the cartons to see if any of th