题目内容
Between now(June) and Labor Day, millions of American will offer up their bodies to the sun’s rays. A tan indicates health and beauty, and most sun worshippers will sacrifice a lot to achieve it—including themselves. With each hour, the sun’s ultraviolet radiation produces irreversible damage, hastening the development of unsightly wrinkles. And with each year on the beach or rooftop, the sunbather increases his risk of getting skin cancer.Skin cancer is by far the most common form of cancer. An estimated 400000 new cases will be detected this year in the United States, and almost all of them can be blamed on overexposure to the sun. Fortunately, most of these cancers are highly curable. But they can be disfiguring and take time to treat. For that reason, sun worshippers should treat deity with a good deal of awe.Sunburn, of course, is the initial hazard posed by UV radiation. Prolonged exposure to UV, however, interferes with the production of collagen fibers in the dermis, causing the skin to lose elasticity and creating premature wrinkles. Further deterioration of the dermis deprives the epidermis of nutrition and causes it to become thin and dry.Cancer is UV’s final insult. Short-wave radiant energy, especially from the UV-B band, breaks the strands of DNA. Enzymes work constantly to rearrange the DNA into proper sequence, but with repeated UV exposure, the repair process may eventually break down. Then the mutant DNA may produce a colony of cancer cells.But skin cancer may be avoided with a good dose of common sense. People with fair skin and blue eyes who burn easily stand the highest risk. Special danger spots are the parts of the body most constantly exposed to the sun, such as the cheeks, nose, lower lip and the ears. People who have already developed precancerous lesions or had one skin cancer growth stand a greatly increased chance of developing others. Dermatologists recommend avoiding the sun when it is most intense—between 11 a.m. and 3 p.m. Anyone who insists on sunbathing should use a good sun screen. These lotions and salves contain chemicals, such as paraaminobenzoic acid, that block out the burning UV-B radiation while permitting the tanning rays to reach the skin. The word "deity" in the second paragraph refers to（）
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Cancer develops over a long time, which means that you have years——typically decades——in which to hinder or promote it. Researchers are finding that what you eat may interfere with cancer growth at various stages. For example, certain foods can block the chemicals that initate cancer. Antioxidants(抗氧化剂), found in some vitamins and minerals, can snuff out oxygen free radicls (氧自由基), substances that are thought to make cells more susceptible to cancer, and they can even repair some of the cellular damage that has been done. And some food—wheat bran(麦,糠) in particular—has been shown to shrink precancerous(癌症前期的) cells.A recent review of 17 studies from 17 nations reveals that people who eat the most fruits and vegetables have about half the cancer raters of those who eat the least. In fact, some research suggests that frequent consumption of fruits and vegetables can cut the risk of lung cancer even in smokers.One of the most studied antioxidants in vegetables and fruits thought to protect against cancer is beta-carotene(β胡萝卜素), concentrated in deep green, yellow and orange vegetables such as carrots, sweet potatoes and spinach.Research also shows that beta-carotene can change in the body to retinoic acid (维生素A酸), a substance used in clinical trials to treat certain cancers.Here are some of the foods that contain cancer-fighting chemicals.Tomatoes. One of the compounds in tomatoes that is thought to reduce the risk of cancer is lycopene(蕃茄素), the pigment (色素) that makes tomatoes red. Lycopene, an antioxidant that is also found in watermelons and apricots, quenches certain cancer-triggering oxygen free fadicals. Healthy people with the most blood lycopene.Green Vegetables. A recent Italian study showed that dark-green leafy vegetables lower the risk of many cancer. Spinach, broccoli, kale and dark-green lettuces are chock-full of antioxidants, including beta-carotene, folate(叶酸) and lutein(叶黄素).A good rule of thumb(单凭经验的做法) : the darker the vegetable, the more antioxidants within.Pungent preventives(刺激性的预防物). A whole host of chemicals thought to have cancer-inhibiting properties have been identified in allium vegetables, which include garlic, onions and scallions(大葱). Animal studies show that many of these chemicals block carcinogens that have been linked to colon, stomach, lung and liver cancer. A study at Pennsylvania State University found that feeding rats various garlic extracts and preparations(配制好的食物) reduced mammary tumors by as much as 71 percent. In humans, studies suggest that those who eat more onions and garlic are less prone to gastrointestinal cancer.Research suggests that garlic compounds may even interfere with cancer progression. A recent German study found that ajoene, a garlic compound, is toxic to malignant cells. Garlic may also antagonize existing cancer by boosting(促进) immune functions, according to researchers at Loma Linda University School of Medicine. Their study, done on mice, found that garlic’s sulfur compounds increased the activity of macrophages and T-lymphocytes(淋巴细胞), two of the components of the immune system that destroy tumor ceils. Citrus fruit may be particularly effective in reducing the risk of pancreatic cancer.（）
Cancer develops over a long time, which means that you have years——typically decades——in which to hinder or promote it. Researchers are finding that what you eat may interfere with cancer growth at various stages. For example, certain foods can block the chemicals that initate cancer. Antioxidants(抗氧化剂), found in some vitamins and minerals, can snuff out oxygen free radicls (氧自由基), substances that are thought to make cells more susceptible to cancer, and they can even repair some of the cellular damage that has been done. And some food—wheat bran(麦,糠) in particular—has been shown to shrink precancerous(癌症前期的) cells.A recent review of 17 studies from 17 nations reveals that people who eat the most fruits and vegetables have about half the cancer raters of those who eat the least. In fact, some research suggests that frequent consumption of fruits and vegetables can cut the risk of lung cancer even in smokers.One of the most studied antioxidants in vegetables and fruits thought to protect against cancer is beta-carotene(β胡萝卜素), concentrated in deep green, yellow and orange vegetables such as carrots, sweet potatoes and spinach.Research also shows that beta-carotene can change in the body to retinoic acid (维生素A酸), a substance used in clinical trials to treat certain cancers.Here are some of the foods that contain cancer-fighting chemicals.Tomatoes. One of the compounds in tomatoes that is thought to reduce the risk of cancer is lycopene(蕃茄素), the pigment (色素) that makes tomatoes red. Lycopene, an antioxidant that is also found in watermelons and apricots, quenches certain cancer-triggering oxygen free fadicals. Healthy people with the most blood lycopene.Green Vegetables. A recent Italian study showed that dark-green leafy vegetables lower the risk of many cancer. Spinach, broccoli, kale and dark-green lettuces are chock-full of antioxidants, including beta-carotene, folate(叶酸) and lutein(叶黄素).A good rule of thumb(单凭经验的做法) : the darker the vegetable, the more antioxidants within.Pungent preventives(刺激性的预防物). A whole host of chemicals thought to have cancer-inhibiting properties have been identified in allium vegetables, which include garlic, onions and scallions(大葱). Animal studies show that many of these chemicals block carcinogens that have been linked to colon, stomach, lung and liver cancer. A study at Pennsylvania State University found that feeding rats various garlic extracts and preparations(配制好的食物) reduced mammary tumors by as much as 71 percent. In humans, studies suggest that those who eat more onions and garlic are less prone to gastrointestinal cancer.Research suggests that garlic compounds may even interfere with cancer progression. A recent German study found that ajoene, a garlic compound, is toxic to malignant cells. Garlic may also antagonize existing cancer by boosting(促进) immune functions, according to researchers at Loma Linda University School of Medicine. Their study, done on mice, found that garlic’s sulfur compounds increased the activity of macrophages and T-lymphocytes(淋巴细胞), two of the components of the immune system that destroy tumor ceils. People who eat the most fruits and vegetables have less than half the cancer rates of those who eat the least.（）
Between now(June) and Labor Day, millions of American will offer up their bodies to the sun’s rays. A tan indicates health and beauty, and most sun worshippers will sacrifice a lot to achieve it—including themselves. With each hour, the sun’s ultraviolet radiation produces irreversible damage, hastening the development of unsightly wrinkles. And with each year on the beach or rooftop, the sunbather increases his risk of getting skin cancer.Skin cancer is by far the most common form of cancer. An estimated 400000 new cases will be detected this year in the United States, and almost all of them can be blamed on overexposure to the sun. Fortunately, most of these cancers are highly curable. But they can be disfiguring and take time to treat. For that reason, sun worshippers should treat deity with a good deal of awe.Sunburn, of course, is the initial hazard posed by UV radiation. Prolonged exposure to UV, however, interferes with the production of collagen fibers in the dermis, causing the skin to lose elasticity and creating premature wrinkles. Further deterioration of the dermis deprives the epidermis of nutrition and causes it to become thin and dry.Cancer is UV’s final insult. Short-wave radiant energy, especially from the UV-B band, breaks the strands of DNA. Enzymes work constantly to rearrange the DNA into proper sequence, but with repeated UV exposure, the repair process may eventually break down. Then the mutant DNA may produce a colony of cancer cells.But skin cancer may be avoided with a good dose of common sense. People with fair skin and blue eyes who burn easily stand the highest risk. Special danger spots are the parts of the body most constantly exposed to the sun, such as the cheeks, nose, lower lip and the ears. People who have already developed precancerous lesions or had one skin cancer growth stand a greatly increased chance of developing others. Dermatologists recommend avoiding the sun when it is most intense—between 11 a.m. and 3 p.m. Anyone who insists on sunbathing should use a good sun screen. These lotions and salves contain chemicals, such as paraaminobenzoic acid, that block out the burning UV-B radiation while permitting the tanning rays to reach the skin. The last paragraph of the passage mainly discusses（）
Cancer develops over a long time, which means that you have years——typically decades——in which to hinder or promote it. Researchers are finding that what you eat may interfere with cancer growth at various stages. For example, certain foods can block the chemicals that initate cancer. Antioxidants(抗氧化剂), found in some vitamins and minerals, can snuff out oxygen free radicls (氧自由基), substances that are thought to make cells more susceptible to cancer, and they can even repair some of the cellular damage that has been done. And some food—wheat bran(麦,糠) in particular—has been shown to shrink precancerous(癌症前期的) cells.A recent review of 17 studies from 17 nations reveals that people who eat the most fruits and vegetables have about half the cancer raters of those who eat the least. In fact, some research suggests that frequent consumption of fruits and vegetables can cut the risk of lung cancer even in smokers.One of the most studied antioxidants in vegetables and fruits thought to protect against cancer is beta-carotene(β胡萝卜素), concentrated in deep green, yellow and orange vegetables such as carrots, sweet potatoes and spinach.Research also shows that beta-carotene can change in the body to retinoic acid (维生素A酸), a substance used in clinical trials to treat certain cancers.Here are some of the foods that contain cancer-fighting chemicals.Tomatoes. One of the compounds in tomatoes that is thought to reduce the risk of cancer is lycopene(蕃茄素), the pigment (色素) that makes tomatoes red. Lycopene, an antioxidant that is also found in watermelons and apricots, quenches certain cancer-triggering oxygen free fadicals. Healthy people with the most blood lycopene.Green Vegetables. A recent Italian study showed that dark-green leafy vegetables lower the risk of many cancer. Spinach, broccoli, kale and dark-green lettuces are chock-full of antioxidants, including beta-carotene, folate(叶酸) and lutein(叶黄素).A good rule of thumb(单凭经验的做法) : the darker the vegetable, the more antioxidants within.Pungent preventives(刺激性的预防物). A whole host of chemicals thought to have cancer-inhibiting properties have been identified in allium vegetables, which include garlic, onions and scallions(大葱). Animal studies show that many of these chemicals block carcinogens that have been linked to colon, stomach, lung and liver cancer. A study at Pennsylvania State University found that feeding rats various garlic extracts and preparations(配制好的食物) reduced mammary tumors by as much as 71 percent. In humans, studies suggest that those who eat more onions and garlic are less prone to gastrointestinal cancer.Research suggests that garlic compounds may even interfere with cancer progression. A recent German study found that ajoene, a garlic compound, is toxic to malignant cells. Garlic may also antagonize existing cancer by boosting(促进) immune functions, according to researchers at Loma Linda University School of Medicine. Their study, done on mice, found that garlic’s sulfur compounds increased the activity of macrophages and T-lymphocytes(淋巴细胞), two of the components of the immune system that destroy tumor ceils. Beta-carotene is one of the most studied antioxidants that are thought to protect against cancer.（）
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