问题 单项选择题 A1型题

外源性致热原的特点,正确的是()。

A.分子量较小

B.其致热原性可被蛋白酶类所破坏

C.能激活血液中的中性粒细胞和单核细胞

D.直接作用于体温调节中枢

E.在体内最终由肝、肾灭活和排泄

答案

参考答案:C

解析:引起传染性发热的生物病原体或其产物,称为外源性致热原。致热原细胞被激活后所形成并释放的致热原称为内源性致热原(EP),为不耐热的小分子蛋白质,致热作用容易被破坏,当EP到达下丘脑后,使下丘脑释放某些介质,使体温调定点上移引起发热,这些介质称为中枢发热介质。外源性致热原不能通过血脑屏障,可激活血液中中性粒细胞和单核细胞。

单项选择题
阅读理解

Ever wondered why some businesses fail and others seem to go from strength to strength(越来越兴旺发达)? One of the major reasons for success or failure in any business is the choice of location. The ABS can be of great help in choosing the most likely place to set up your business. Whether it’s simple or a complex business.

Case study one

A Sydney doctor specializing pediatrics(小儿科) was hoping to set up a practice outside the metropolitan area, probably on the northern coast of New South Wales. He was unsure of the best place in this region and came to the ABS for help. The ABS was able to put together a report containing details of the proportion of the children in particular areas, along with information on regions with the highest birth rates. This enabled the doctor to work out where future demand for his services would be.

Case study two

A suburban retailer(零售商)in Perth owned a shoe store which stocked a wide range of shoes for men, women and children. There had been an increase in the number of similar shoe stores in the suburban shopping center and the owner wanted to assess the possibility of switching to selling imported shoes and handbags for women only. In order to ensure whether there was a market for these products, the retailer needed to obtain details of income by age, sex, and occupation for all the women in the city of Perth. Using information from the 1996 Census(普查)of Population and Housing, the ABS was able to provide this type of information in a detailed report. With the information, the retailer was able to believe that there were enough professional working women in the area with middle to high incomes, which makes his business possible.

1. What information did the Sydney doctor get from the ABS about the northern coast of New South Wales?

A. The number of medical practices there.

B. The detailed information about the children.

C. Its present and future economic situations.

D. The ideal place to start a practice there.

2. The retailer wanted to switch to selling imported shoes and handbags for women because________.

A. there were more and more working women

B. he wanted to enlarge the original store

C. there were more and more shoe stores

D. imported products were popular

3. What does the ABS do for its customers?

A. Doing research work in the fields.

B. Suggesting the most potential market.

C. Providing considerable amounts of data.

D. Predicting the possible consumer goods.

4. This passage is most probably a(n) _____________.

A. handout for management           B. income report

C. advertisement                   D. plan for a project