问题 多项选择题 案例分析题

萤火虫能发光是因为萤火虫体内通过荧光素酶催化的系列反应所产生的现象。如果荧光素酶存在于植物体内,也可使植物体发光。一直以来,荧光素酶的唯一来源是从萤火虫腹部提取。但加利福尼亚大学的一组科学家成功地通过转基因工程将荧光素酶基因导入到大肠杆菌体内,并在大肠杆菌体内生产荧光素酶。请你根据已有的知识回答下列有关问题:

将此目的基因导入到大肠杆菌体内需要运载体的帮助。下列选项是选取运载体的时候必须考虑的有()。

A.能够在宿主细胞内复制并稳定保存

B.具有特定的限制酶切点

C.具有与目的基因相同的碱基片断

D.具有某些标记基因

答案

参考答案:A, B, D

阅读理解

On December 8, Xinhua News Agency published a list of news keywords that it believes sum up the year 2009.

The phrase “low-carbon life” had been heard in China before 2009, but in 2009, it has become popular among young Chinese who are concerned about the environment. It comes as world leaders are talking about fighting global warming in Copenhagen, Denmark. Greenhouse gases, such as carbon dioxide, are the main cause of global warming, which leads to extreme weather and other conditions.

Living a low carbon life means trying to cut carbon dioxide emissions(排放) in one’s daily life. For example, burning less coal and oil, which produce CO2. It means walking, biking or taking buses, rather than using a private car.

“A(H1N1) flu” is also on Xinhua’s list. Since April, 2009 the virus has made over 100,000 people ill on the Chinese mainland and 325 people had died of it as of December 9. But as US magazine Newsweek pointed out recently, the best evidence suggests it is no more dangerous than a bad seasonal flu.

The year 2009 saw the growing impact of the Internet on society, with the word “duomaomao”, meaning hide-and-seek, becoming a hit on the web. On February 12, Li Qiaoming died of brain injuries several days after being detained(拘留) by police in Jinning county, Yunnan Province. Police said it was an accident sustained(遭受)while he was playing hide-and-seek with his fellow prisoners. Netizens cast doubt on this explanation and called for an investigation. It turned out that Li had been beaten to death by other prisoners.

Another phrase connected with the Internet on the list is “Net Addiction Camps”. Many parents send children obsessed(沉迷) with the web to “Net Addiction Camps” for treatment. But some camps use physical punishment or electrical shocks. In 2009, some young people died as a result of the extreme methods, which led to a nationwide discussion. In November, the Ministry of Health banned the use of physical punishment to keep children off the net and dropped the term “net addiction(网瘾)”. It did not say that excessive(过度的) net use is a mental illness either.

66. The purpose of the passage is to ___________.

A. call on the public to live a low-carbon life

B. show the great effect of the Internet

C. introduce some news keywords of the year 2009

D. warn people not to be addicted to the Internet

67. The underlined word “Netizens” in the fifth paragraph refer to_________.

A. Li’s fellow prisoners

B. Li’s friends and relatives

C. the local people

D. people actively involved in online communities

68. What can be inferred from the incident of “duomaomao”?

A. Hide-and-seek is a dangerous game.

B. Li was beaten to death by other prisoners.

C. Police did a great job in the investigation (调查).

D. It was the influence of the Internet that led to the truth.

69. Which of the following is TRUE according to the passage?

A. The phrase “low-carbon life” had been popular among young people before 2009.

B. Global warming mainly results from greenhouse gases.

C. A (H1N1) flu is more dangerous than a bad seasonal flu.

D. Li Qiaoming died of an accident while playing hide-and-seek with his fellow prisoners.

70. Which of the following doesn’t mean a low-carbon life ?

A. Using a private car.

B. Using efficient light bulbs.

C. Walking, biking or taking buses.

D. Turning your air-conditioner one degree higher.

单项选择题