问题 单项选择题

有关免疫球蛋白和抗体的说法,正确的是

A.免疫球蛋白就是抗体、两者具有相同的含义

B.免疫球蛋白均为抗体,抗体不一定都是免疫球蛋白

C.免疫球蛋白与抗体不同,两者也不相关

D.抗体均为免疫球蛋白,而免疫球蛋白并不一定都是抗体

E.抗体和免疫球蛋白只存在于血液和体液中,两者均具有免疫功能

答案

参考答案:D

解析:免疫球蛋白是指具有抗体活性和化学结构与抗体相似的球蛋白。抗体是指浆细胞合成分泌的能与相应抗原特异性结合具有免疫功能的球蛋白。免疫的内容,除抗体外还包括膜表面免疫球蛋白(如Smlg)和一类结构与抗体相似,但无免疫功能的球蛋白。

阅读理解

Bells sound. Lighted messages appear. Men and women work at computers. They talk on the telephone. At times they shout and run around.

This noisy place is a stock exchange (证券交易所). Here expert salespeople called brokers buy and sell shares(股份) of companies. The shares are known as stocks. People who own stock in a company own part of that company.

People pay brokers to buy and sell stocks for them. If a company earns money, its stock increases in value. If the company does not earn money, the stock decreases in value. Brokers and investors(投资者)carefully watch for any changes on the Big Board. That is the name given to a list of stocks sold on the New York Stock Exchange.

Investors and brokers watch the Big Board to see if the stock market is a bull market or a bear market. In a bear market, prices go down. In a bull market, prices go up.

Investors in a bear market promise to sell a stock in the future at a set price. But the investor does not own the stock yet. He or she waits to buy it when the price drops.

The meaning of a bear market is thought to come from an old story about a man who sold the skin of a bear before he caught the bear. An English dictionary of the sixteen hundreds said, to sell a bear is to sell what one has not.

Word experts dispute the beginnings of the word bull in the stock market. But some say it came from the long connection of the two animals – bulls and bears – in sports that were popular years ago in England.

Investors always care about the possibility of a company failing. In the modern world, a company that does not earn enough profit (利润)is said to go belly up. A company that goes belly up dies like a fish. Fish turn over on their backs when they die. So they are stomach, or belly up.

Stock market investors do not want that to happen to a company. They want a company whose stock they own to earn more profit than expected. This would sharply increase the value of the stock. Investors are hoping for a windfall(横财).

72. The first paragraph is written for the purpose of ________.

A. making readers interested in buying stocks

B. telling readers the place is so busy

C. telling readers people in the stock exchange are busy

D. attracting readers’ attention to the topic of the passage

73. A fresher of a stock market probably turns to a (n) _______ for advice.

A. company                                 B. investor

C. broker                                   D. word expert

74. John bought his stock from a company which has gone belly up this year. We can infer _________ .

A. John would lose money this year

B. John would earn money this year

C. the stock market is a bear market

D. the stock market is a bull market

75. The reason why investors pay attention to the company whose stock they own is that _______ .

A. the company belongs to them

B. the company earns much money

C. they work for the company

D. they are financially connected with the company

单项选择题