Flying over a desert area in an airplane, two scientists looked down with trained eyes at trees and bushes. After an hour’s flight one of the scientists wrote in his book, "Look here for probable metal. " Scientists in another airplane, flying over a mountain area, sent a message to other scientists on the ground, "Gold possible. " Walking across hilly ground, four scientists reported. "This ground should be searched for metal." From an airplane over a hilly wasteland a scientist sent back by radio one word: "Uranium."
None of the scientists had X-ray eyes: they had on magic powers of looking down below the earth’s surface, They were merely putting to use one of the newest methods of locating minerals in the ground, using trees and plants as signs that certain minerals may lie beneath the ground on which the trees and plants are growing.
This newest method of searching for minerals is based on the fact that minerals deep in the earth may affect the kind of bushes and trees that grow on the surface.
At Weston Bar Greek, a brook six thousand feet high in the mountains of British Columbia, Canada, a mineral search group gathered bags of tree seeds. Boxes were filled with small branches from the trees. Roots were dug and put into boxes. Each bag and box was carefully marked. In a scientific laboratory the parts of the forest trees were burned to ashes and tested. Each small part was examined to learn whether there were minerals in it.
Study of the roots, branches, and seeds showed no silver. But there were small amounts of gold in the roots and a little less gold in the branches and seeds. The seeds growing nearest to the tree trunk had more gold than those growing on the ends of the branches.

Scientists were flying over a desert of a hilly waste（　）land or a mountain area in order to search for in the ground.

A:gold B:silver C:metal D:minerals

Vegetarianism A strict vegetarian is a person who never in his life eats anything derived from animals. The main objection to vegetarianism on a long-term basis is the difficulty to getting enough protein, the body building elements in food. If you have ever been without meat or animal foods for some days of weeks(say, religious reasons) you will have noticed that you tend to get physically rather weak. You are glad when the fast is over and you get your reward of a succulent meat meal. Proteins are built up from approximately twenty food elements called "amino-acids", which are found more abundantly in animal protein than in vegetable protein. This means you have to eat a great deal more vegetable than animal food in order to get enough of these amino-acids. A great of the vegetable food goes to waste in this process and from the physiological point of view there is not much to be said in favor of life-long vegetarianism. The economic side of the question, though, must be considered. Vegetable food is much cheaper than animal food. However, since only a small proportion of the vegetable protein is useful for body-building purposes, a consistent vegetarian, if he is to gain the necessary 70 grams of protein a day, has to consume a greater bulk of food than his digestive organs can comfortably deal with. In fairness, though, it must be pointed out that vegetarians claim they need far less than 70 grams of protein a day. Whether or not vegetarianism should be advocated for adults, it is definitely unsatisfactory for growing children, who need more protein than they can get from vegetable source’’s. A lacto-vegetarian diet, which includes milk and milk products such as cheese, can, however, be satisfactory as long as enough milk and milk products are consumed. Meat and cheese are the best sources of usable digestible and next come milk, fish and eggs. Slow and careful cooking of meat makes it more digestible and assists in the breaking down of the protein content by the body. When cooking vegetables, however, the vitamins, and in particular the water-solube vitamin C, should be lost through overcooking. Compared with vegetable food animal food contains______.

A:more proteins B:more nutrients C:more minerals D:more amino-acids

{{B}}第三篇{{/B}}

Which of the following can be concluded from this passage?

A:China’s gold and silver reserves are among the largest in the world. B:China’s reserves of minerals are among the largest in the world. C:The development of science and technology will guarantee the discovery of more minerals. D:The prospects for more minerals are gloomy.

{{B}}第三篇{{/B}}

Compared with vegetable food animal food contains______.

A:more proteins B:more nutrients C:more minerals D:more amino-acids

Vegetarianism A strict vegetarian is a person who never in his life eats anything derived from animals. The main objection to vegetarianism on a long-term basis is the difficulty to getting enough protein, the body building elements in food. If you have ever been without meat or animal foods for some days of weeks(say, religious reasons) you will have noticed that you tend to get physically rather weak. You are glad when the fast is over and you get your reward of a succulent meat meal. Proteins are built up from approximately twenty food elements called "amino-acids", which are found more abundantly in animal protein than in vegetable protein. This means you have to eat a great deal more vegetable than animal food in order to get enough of these amino-acids. A great of the vegetable food goes to waste in this process and from the physiological point of view there is not much to be said in favor of life-long vegetarianism. The economic side of the question, though, must be considered. Vegetable food is much cheaper than animal food. However, since only a small proportion of the vegetable protein is useful for body-building purposes, a consistent vegetarian, if he is to gain the necessary 70 grams of protein a day, has to consume a greater bulk of food than his digestive organs can comfortably deal with. In fairness, though, it must be pointed out that vegetarians claim they need far less than 70 grams of protein a day. Whether or not vegetarianism should be advocated for adults, it is definitely unsatisfactory for growing children, who need more protein than they can get from vegetable source’’s. A lacto-vegetarian diet, which includes milk and milk products such as cheese, can, however, be satisfactory as long as enough milk and milk products are consumed. Meat and cheese are the best sources of usable digestible and next come milk, fish and eggs. Slow and careful cooking of meat makes it more digestible and assists in the breaking down of the protein content by the body. When cooking vegetables, however, the vitamins, and in particular the water-solube vitamin C, should be lost through overcooking. Compared with vegetable food animal food contains______.

A:more proteins B:more nutrients C:more minerals D:more amino-acids

Vegetarianism A strict vegetarian is a person who never in his life eats anything derived from animals. The main objection to vegetarianism on a long-term basis is the difficulty to getting enough protein, the body building elements in food. If you have ever been without meat or animal foods for some days of weeks(say, religious reasons) you will have noticed that you tend to get physically rather weak. You are glad when the fast is over and you get your reward of a succulent meat meal. Proteins are built up from approximately twenty food elements called "amino-acids", which are found more abundantly in animal protein than in vegetable protein. This means you have to eat a great deal more vegetable than animal food in order to get enough of these amino-acids. A great of the vegetable food goes to waste in this process and from the physiological point of view there is not much to be said in favor of life-long vegetarianism. The economic side of the question, though, must be considered. Vegetable food is much cheaper than animal food. However, since only a small proportion of the vegetable protein is useful for body-building purposes, a consistent vegetarian, if he is to gain the necessary 70 grams of protein a day, has to consume a greater bulk of food than his digestive organs can comfortably deal with. In fairness, though, it must be pointed out that vegetarians claim they need far less than 70 grams of protein a day. Whether or not vegetarianism should be advocated for adults, it is definitely unsatisfactory for growing children, who need more protein than they can get from vegetable source’’s. A lacto-vegetarian diet, which includes milk and milk products such as cheese, can, however, be satisfactory as long as enough milk and milk products are consumed. Meat and cheese are the best sources of usable digestible and next come milk, fish and eggs. Slow and careful cooking of meat makes it more digestible and assists in the breaking down of the protein content by the body. When cooking vegetables, however, the vitamins, and in particular the water-solube vitamin C, should be lost through overcooking. Compared with vegetable food animal food contains______.

A:more proteins B:more nutrients C:more minerals D:more amino-acids

Vegetarianism A strict vegetarian is a person who never in his life eats anything derived from animals. The main objection to vegetarianism on a long-term basis is the difficulty to getting enough protein, the body building elements in food. If you have ever been without meat or animal foods for some days of weeks(say, religious reasons) you will have noticed that you tend to get physically rather weak. You are glad when the fast is over and you get your reward of a succulent meat meal. Proteins are built up from approximately twenty food elements called "amino-acids", which are found more abundantly in animal protein than in vegetable protein. This means you have to eat a great deal more vegetable than animal food in order to get enough of these amino-acids. A great of the vegetable food goes to waste in this process and from the physiological point of view there is not much to be said in favor of life-long vegetarianism. The economic side of the question, though, must be considered. Vegetable food is much cheaper than animal food. However, since only a small proportion of the vegetable protein is useful for body-building purposes, a consistent vegetarian, if he is to gain the necessary 70 grams of protein a day, has to consume a greater bulk of food than his digestive organs can comfortably deal with. In fairness, though, it must be pointed out that vegetarians claim they need far less than 70 grams of protein a day. Whether or not vegetarianism should be advocated for adults, it is definitely unsatisfactory for growing children, who need more protein than they can get from vegetable source’’s. A lacto-vegetarian diet, which includes milk and milk products such as cheese, can, however, be satisfactory as long as enough milk and milk products are consumed. Meat and cheese are the best sources of usable digestible and next come milk, fish and eggs. Slow and careful cooking of meat makes it more digestible and assists in the breaking down of the protein content by the body. When cooking vegetables, however, the vitamins, and in particular the water-solube vitamin C, should be lost through overcooking. Compared with vegetable food animal food contains______.

A:more proteins B:more nutrients C:more minerals D:more amino-acids