此试题出现在
2.01，2.02，2.03，（ ），2.08，2.13。
Directions:In this section, there is one passage followed by a summary. Read the passage carefully and complete the summary below by choosing a maximum of three words from the passage to fill in the spaces 76-80. Remember to write the answers on the Answer Sheet. Questions 1-5 are based on the following passage. Headaches are a big problem. But they are not just a problem for the person suffering from the headache. They are a problem for society as well. Each year, millions of people suffer from severe headaches that keep them from doing their jobs. In fact, according to one estimate, headaches cost individuals and businesses more than $50 billion each year! This is one of the reasons research into headaches has become a worldwide effort. Although he did not know much about how headaches work, Hippocrates was the first doctor to find a way to treat them. Before 400 B.C., Hippocrates discovered that the bark from willow trees was useful in treating pain. He made a white powder from the tree’s bark and gave it to his patients. Hippocrates did not know it, but he was actually prescribing a natural chemical in willow bark called salicin. When a person eats salicin, the chemical is changed inside her or his body into salicylic acid. It turns out that salicylic acid is good for stopping pain, including headache, but it is bad for a person’s stomach. In the 1800s, a chemist in Germany changed the acid’s form a little to make it easier for people to take. This new form of the chemical was called acetylsalicylic acid, commonly known as aspirin today. Aspirin was used throughout most of the 1900s to treat headaches, but doctors had little idea about what really caused headaches. When doctors know the cause of a disease, they can find better ways to treat it. Therefore, as medical technology developed, doctors began to use the technology to learn more about the human brain and about headaches. Currently, doctors classify headaches into two general types: primary and secondary. A primary headache is a condition suffered as only the headache itself. On the other hand, a secondary headache is one caused by another condition. For example, someone who catches the flu may suffer from headaches along with other symptoms of the illness. Flu headaches are thus secondary headaches. For primary headaches, doctors have determined three possible causes. One kind of primary headache is caused by stress. Doctors usually call these tension headaches. Such headaches are characteristically felt on both sides of the head as a dull, steady pain.Another kind of primary headache is the migraine headache. Doctors believe these headaches are caused by reduced flow of blood to certain parts of the brain. A migraine sufferer usually feels intense pain on one side of the head. The sufferer also becomes sensitive to light and noise. If the migraine is severe, the sufferer may vomit repeatedly. The third kind of primary headache is known as the cluster headache. Cluster headaches typically occur around the same time each day for weeks or months at a time. The person suffering from this kind of headache usually feels pain on one side of her or his head, and the pain is centered around one of the person’s eyes. Doctors do not know much at present about cluster headaches, but they seem more common among men and could be related to alcohol or other things that affect a person’s blood flow. Using computers and more advanced medical equipment, doctors continue to learn more about what happens in the brain before and during headaches. Especially in the case of migraines, some doctors believe they have found the part of the brain that sets off the reaction for severe attacks. With this new insight into brain processes, doctors hope new ways will be discovered for stopping disabling headaches before they begin. Summary: Doctors knew a long time ago that the 1 from the willow trees could help people who felt pain. Hippocrates was the first doctor to change organic material into a powder and give it to his patients. But it was not until the 1800s that this natural drug was altered and became known as 2 . With the help of technology, doctors have now gained detailed insight into how the brain works and what happens when a person suffers from a headache. Through this research, headaches have been 3 primary and secondary headaches. There are three types of primary headaches: tension, migraine, and cluster headaches. Although not much is known about cluster headaches, doctors have been able to determine some of the things that 4 During a migraine attack, the sufferer may become 5 and noise.
康明斯柴油机型号中AFC的含义是（）。
（）是民族的下位概念，即一个民族由若干个这样的单位组合而成。
证券市场按其职能分类可以有（）
在一维双原子链中，如M/m〉〉1,求证
女性，40岁，下肢水肿，查体：心尖区限局性舒张期隆隆杂音，肺部听诊正常，肝大（-），腹水（-），双下肢水肿（+）及皮肤呈暗紫色，右侧重于左侧。月经期未检查尿。该患者下肢水肿最可能的原因是（）
肾癌的三大典型症状（）。
（ ）是指根据客户的需要和客户对产品某种属性的重视程度，设计出区别于竞争对手的具有鲜明个性的产品，让产品在未来客户的心目中找到一个恰当的位置。
根据产品实体在价值链各环节的流转程序，企业的价值活动上有环节和下游环节，上游环节的中心是产品，下有环节的中心是营销。