Humans and many other mammals have unusually efficient internal temperature regulating systems that automatically maintain stable core body temperatures in cold winters and warm summers. In addition, people have developed cultural patterns and technologies that help them adjust to extremes of temperature and humidity . In very cold climates, there is a constant danger of developing hypothermia , which is a life threatening drop in core body temperature to below normal levels. The normal temperature for humans is about 37.0degC. However, differences in persons and even the time of day can cause it to be as much as 6degC higher or lower in healthy individuals. It is also normal for core body temperature to be lower in elderly people. Hypothermia begins to occur when the core body temperature drops to 34.4degC. Below 29.4degC, the body cools more rapidly because its natural temperature regulating system usually fails. The rapid decline in core body temperature is likely to result in death. However, there have been rare cases in which people have been saved after their temperatures had dropped to 13.9-15.6degC. This happened in 1999 to a Swedish woman who was trapped under an ice sheet in freezing water for 80 minutes. She was found unconscious, not breathing, and her heart had stopped beating, yet she was eventually saved despite the fact that her temperature had dropped to 13.7degC. In extremely hot climates or as a result of uncontrollable infections, core body temperatures can rise to equally dangerous levels. This is hyperthermia. Life threatening hyperthermia typically starts in humans when their temperatures rise to 40.6-41.7degC. Only a few days at this extraordinarily high temperature level is likely to result in the worsening of internal organs and death. People are unlikely to survive under the body temperature _ . A) higher than 34.4degC B) lower than 29.4degC C) between 40.6-41.7degC D) between 34.4-37degC
B
My interest in Chinese food started years a90, when l was a young reporter for the Washington Post. Our office wasn't far from Chinatown, where I found some very good Chinese restaurants. The first time I ever ate Chinese food I loved it. I noticed the fresh taste of the meat and vegetables. When I learned more about the food, I began to understand why it has this special feature. Many years ago, China had an energy crisis because it lost much of its wood due to over population and poor management of its forests. This loss was very bad for the country, of course, but it turned out to be very good for the food. Wood became very expensive and hard to get,so the Chinese had to either find a substitute for their valuable wood,or learn how to use it better. There weren't any substitutes so people found ways to economize. In order to economize in cookin9, they had to use very little wood. So they started cutting their meat and vegetables into small pieces before they put them in the hot oil.That way,the food cooked faster and they saved their fuel. The food prepared in this way kept its fresh flavorand it's this flavor that attracts people from other countries to the art of Chinese cooking. The author mentioned the energy crisis to show _ . A) it is important to protect the forests B) it is necessary to find substitutes for wood C) why the Chinese changed their way of cooking D) what problems a big population is causing China today
C
Q: My experience in learning English is very simple. I am at the level that almost everyone can reach. Though I focused on English for over two years, an English expert or a native speaker can easily find out my problems--the lack of professional learning, mistakes throughout my writings, and sentences and expressions based on Chinese thoughts. Though I have many weaknesses in English, I have harvested a lot of things many people at my age wish to have. This proves that English, considered a subject that can hardly be self-taught, may be acquired through everyday learning and practice. Some of my friends, including my parents, think it is a miracle . They believe it is my perseverance that helps me learn English. It helps, I admit, but it deserves not all the credit. I don't know yet if it's difficult to overcome my weaknesses, but I know I'll be proud of myself when I grasp everything that helps improve my English. Many students with English teachers to turn to, English classes to study in and new English learning devices and books to refer to, can't learn English well. Why? To answer that question, I have to ask you, "Why do you learn English?" I may receive many different answers, but there is a direct answer: To use it every day. From this point we know there's great similarity between English and other subjects like maths. Not everyone becomes mathematician, but everyone must learn to use it in daily life. The author learns English _ . A) by himself B) by turning to English teachers C) in English classes D) with the help of his parents
A: A
*Question*
Every foreign student who has been accepted to study in this country must have a legal document called a visa from the prefix = st1 /United Statesgovernment. A visa permits a foreign citizen to travel to theUnited Statesand request permission to enter the country. The rules for getting a visa can be found on the State Department Web site. The address is unitedstatesvisas. gov. Unitedstatesvisas is all one word. Another State Department Web site for students from other countries is educationusa. gov. If you are requesting a visa for the first time, you may have to appear at the American Embassy in your country to talk to an official. Each student should communicate with the Embassy to find out if such an interview is needed and when it can take place. It is important to apply for the visa early. State Department officials say national security is the most important issue in deciding if a person will be permitted to enter the United States. Officials must find out if a student is on any list of people with possible links to terrorists. Embassies can not issue a visa more than ninety days before the start of the educational program in the United States. If you are a student studying in theUnited Statesfor the first time, you will not be permitted to enter the country more than thirty days before the start of your classes. Foreign students accepted at an American school will receive a document called a Certificate of Eligibility. The State Department says each student must enter the country using the certificate provided by the school he or she will be attending. It is a violation of the law to enter the country on one school's certificate but attend another school. You are permitted to stay in the United Stateson a student visa for the length of your period of study. That means you can stay as long as you are a full-time student. Your college or university will provide the government with reports about your education as long as you continue to study there. We will have more information about that next week. To get a visa to the USA, _ . A) none of the students have to talk to American officials B) all foreign students don't have to have an interview with an official in the American embassy in your country C) a foreign student can appear at the American embassy D) all students have to prove they are able to afford the education fee
**Answer**
B