题目内容
级配曲线中，通过量与筛孔尺寸为坐标，级配线靠近范围图上线的砂通过量越小，相对较粗，即靠近下线的砂则相对较粗。()
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水泥强度测定是采用标准稠度的水泥净浆来制作试件。()
材料的孔隙率越大，其强度值越小。()
Many of the most important drugs that doctors prescribe today have been developed in the last 30 years. Modern drugs are complex, specific and powerful. People need to know more about drugs in order to use them safely.
Early people discovered by accident that some of the plants growing around them seemed useful to heal sores, relieve pain, or even cure diseases. These plants were the first drugs. Now plants are still the source of some drugs. Quinine, for example, is a bitter-tasting drug used to treat the chills and fever of malaria and to reduce attacks of the disease. It is made from the bark of the cinchona tree, which grows in the Andes Mountains. The Indians of that region were the first to use the bark as a medicine. The Spanish people probably brought it to Europe in the early 1600s. Chemists learned how to get the pure drug from the bark and in 1944;it was made artificially in the laboratory.
Other important drugs, such as hormones and vaccines, are obtained from animals. But most of the modern drugs come from chemical combinations worked out by research scientists. Most people never see drugs in their simple form. as chemicals. Instead, they are seen as tablets, capsules or liquids that contain the drug and other ingredients.
People use drugs to get different results. Some drugs attack the organism that causes a disease. They cure by killing the organism. Other drugs relieve what we call the symptoms of the disease, the headache, pain, fever or chills, and make the patient more comfortable. These constitute most over-the-counter drugs. People can get them in drug stores.
What is the main idea of this passage？
沥青混合料用粗集料可以采用级配碎石或级配卵石。()
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