根据以下内容回答题：Scientists know that there are two basic approaches to prolonging life（延长寿命），one approache is the elimination of the diseases that generally affect older people—diseases such as cancer，heart attack and stroke．（1）is the delay of the process of growing-old the（2）of the body． In recent years scientific researchers（3）much time in the study of the process of aging．They believe that，within a few years，they will develop the knowledge and the（4）to delay the aging process for lo to 15 years．The result will be that more people will live longer，more healthful lives．At present，scientists believe that with the right diet，exercise，medical（5），and mental attitude many people can live to he l00 years old． Gerontologists（老年学专家），people who（6）studies of the problems of growing old，are investigating（7）body cells slow down and（8）die．They feel that delaying this slowing down process（9）help postpone death．In a number of American universities，scien-tists are studying the activity of cells，the effects of diet and internal body temperature on aging．If their studies are successful，the results should help（10）the quality of life for older people in the next few years，as well as increase the life span of the next generation．

请回答（1）题

查看材料

请以“大学生逃课现象”为话题作文

According to the text，the best host__________ ．

The author of this article may agree with which of the following?

“It would have been bad manners to make his guests feel foolish or uncomfortable．”“bad manners”means __________．

Which of the following do you think is the best tiltle for this passage?

根据以下内容回答题：Social customs and ways of behaving change．Things which were considered impolite many years ago are now acceptable．Just a few years ago，it was considered impolite behavior. for a man to smoke on street．No man who thought of himself by smoking when a lady was in a room． Customs also differ from country to country．Does a man walk on the left or the right of a woman in your country?Or doesn’t it matter?Should you use both hands when you are eating?Should leave one in your lap，or on the table?The Americans and the British not only speak the same language but also share a large number of social customs．For example，in both America and England people shake hands when they meet each other for the first time．Als0．most Englishmen will open a door for a woman or offer their seat to a woman，and SO will most Americans．Promptness is important both in England and in America．That is，if a dinner invitation is for 7 o"clock，the dinner guest either arrives close to that time or calls up to explain his delay． The important thing to remember about social customs is not to do anything that might make other people feel uncomfortable——especially if they are your guests．When the food was served，one of the guests started to eat his meats with a knife．The other guests were amused or shocked，but the host calmly picked up his knife and began eating in the same way．It would have been bad manners to make his guest feel foolish or uncomfortable．

If one has accepted a dinner invitation，what should he do if he is to be late for the dinner?

Which of the following can best replace the phrase“foot the bill”in the first para-graph?

The writer’s attitude towards the annual l2-billion．d011ar business of wedding appears to be __________．

Which of the following is not mentioned?

Not a single company can dominate．the industry because __________．