单选题 Using HIV Virus to Cure Cancer
Scientists are planning to use human immunodeficiency (免疫缺陷) virus (HIV), one of mankind's most feared viruses, as a carrier of genes which can fight cancer and a range of diseases that cannot be cured. The experts say HIV has an almost perfect ability to avoid the body's immune (免疫的) defenses, making it ideal for carrying replacement genes into patients' bodies, according to the Observer.
A team at the California-based Salk Institute, one of the world's leading research centers on biological sciences, has created a special new breed of HIV and has started negotiations with the US Food and Drug Administration (FDA) to begin clinical gene therapy (治疗) trials this year. The first trials are expected to involve patients suffering from cancers that cannot be cured by surgery although project leader Professor Inder Verma said the HIV technique would have "far wider applications".
The plan remains very likely to cause controversy since it involves making use of a virus which has caused more than 22 million deaths around the world in the past two decades. Verma said that the idea of using HIV for a beneficial purpose was "shocking" but the fierce nature of HIV had disappeared by having all six of the potentially deadly genes removed.
Illnesses such as various cancers are caused when a gene in a patient's body fails to work properly. In the past two years, breakthroughs in genetics (遗传学) have led gene therapy scientists to try and replace the genes that do not function normally.
Unfortunately, the body's immune defenses have been known to attack the modified genes and make them lose their effects before they can start their task and progress in the field has been held up by the lack of a suitable carrier.
The HIV virus has the ability to escape from, and then destroy, the immune defense ceils designed to protect our bodies and this makes it attractive to scientists as a way of secretly conveying replacement genes into patients' bodies.

单选题 FDA has approved the plan of using HIV to cure cancer in humans.
A. Right B. Wrong C. Not mentioned
【正确答案】 B
【答案解析】[解析] 利用题干中的特征词FDA和题干中的核心结构“approved the plan”作为答案线索，在文章中查找到相应的句子：A team at the California-based Salk Institute，one of the world's leading research centers on biological sciences，has created a special new breed of HIV and has started negotiations with the US Food and Drug Administration(FDA) to begin clinical gene therapy(治疗)trials this year ．该句包含了我们所选定的两个线索结构，因此判断该句很可能就是直接的答案相关句，该句中的划线结构说“一个研究小组已经就今年进行临床基因疗法实验问题同FDA进行了谈判”，“进行了谈判”并不等于“已经获得批准”，因此判断问题句的说法不正确。
单选题 The idea of using HIV for a beneficial purpose has been widely accepted.
A. Right B. Wrong C. Not mentioned
【正确答案】 B
【答案解析】[解析] 利用题干中的核心结构“The idea”和“has been widely accepted”作为答案线索，这样在文章中查找到答案相关句：The plan remains very likely to cause controversy since it involves making use of a virus which has caused more than 22 million deaths around the world in the past two decades．Verma said that the idea of using HIV for a beneficial purpose was“shocking”but the fierce nature of HIV had disappeared by having all six of the potentially deadly genes removed．划线句中并没有出现问题句中的另一个核心结构has been widely accepted，而且在句意上也只是在说“对HIV病毒进行有益的使用这种想法可能令人震惊，但是去除HIV病毒中的所有六个致命基因就能消除掉HIV凶残的本质”，所以接着注意划线句所在的上下文，上文中提到 (斜体句)“这个计划很可能会引起争议，因为它涉及到使用一种在过去20年中造成2，200万人死亡的病毒”，从这个句意来看，显然斜体句中的“The plan”也就是划线句中的“对HIV病毒进行有益的使用这种想法”，既然这种想法引发争论，当然也就不可能被普遍接受了，所以问题句的说法错误。
单选题 HIV can be safely used to cure cancer only il' the deadly genes have been removed.
A. Right B. Wrong C. Not mentioned
【正确答案】 A
【答案解析】[解析] 利用题干巾的特征结构(修饰结构)“safely”和“the deadly genes”作为答案线索，在文章中找到相关句：Verma said that the idea of using HIV for a beneficial purpose was“shocking”but the fierce nature of HIV had disappeared(“HIV凶残的本性已经消失”对应另一线索词safely)by having all six of the potentially deadly genes removed．该句说“对HIV病毒进行有益的使用这种想法可能令人震惊，但是去除 HIV病毒中的所有六个致命基因就能消除掉HIV凶残的本质”，显然这与问题句“只有当致命基冈被去除了以后，HIV才可以安全地被用于治疗癌症”的内容一致。
单选题 The HIV virus is an excellent warrior to fight the body's immune cells.
A. Right B. Wrong C. Not mentioned
【正确答案】 A
【答案解析】[解析] 利用题干中的特征结构“an excellent warrior”和“the body's immune cells”作为答案线索，这样在文章中找到相应的结构“immune defenses”，发现直接答案相关句：The HIV virus has the ability to escape from，and then destroy(与另一线索词warrior“战士”呼应)，the immune defense cells designed to protect our bodies and this makes it attractive to scientists as away of secretly conveying replacement genes into patients’bodies．这个句子中出现了我们选定的两个线索结构，因此该句很可能就是直接的答案相关句，这个句子说“HIV病毒有能力避开保护我们身体的免疫防御细胞，然后再消灭它们”，根据这个内容判断问题句“HIV病毒是战胜身体免疫细胞的最佳战士”的说法正确。
单选题 Other countries are also expected to begin clinical gene therapy trials soon.
A. Right B. Wrong C. Not mentioned
【正确答案】 C
【答案解析】[解析] 题干中主要信息涉及到其他国家，利用题干中的核心结构“Other countries”作为答案线索，这样发现文章中根本没有提到“Other countries”和其他国家的国名，所以判断该题答案为C。
单选题 It is the lack of money that has held up the progress in using replacement genes to cure cancer.
A. Right B. Wrong C. Not mentioned
【正确答案】 B
【答案解析】[解析] 题干中的核心结构涉及到“缺钱”和“阻止……进程”，利用这样的结构作为答案线索，发现答案相关句：Unfortunately, the body's immune defenses have been known to attack the modified genes and make them lose their effects before they can start their task and progress in the field has been held up by the lack of a suitable carrier．句子中只出现了与其中一个核心结构相关的内容(划线结构)，该结构说“缺少合适的基因携带者使这个领域中的工作停滞不前”，现在解题的关键就是确认“这个领域”与题干中的using replacement genes to cure cancer是否相关，所以关注上下文：上文(In the past two years，breakthroughs in genetics(遗传学)have led gene therapy scientists to try and replace the genes that do not function normally．)说“在过去两年里，遗传学上的研究突破仗研究基因疗法的科学家们尝试替换掉那些不能正常工作的基因”，因此判断划线句中的“the field”就是指“使用替代基因”，因此判断问题句的说法错误(原文提到阻止研究进程的原因是“没有合适的基因载体”，而不是“缺钱”)。
单选题 The HIV virus has caused more deaths in developed countries.
A. Right B. Wrong C. Not mentioned
【正确答案】 C
【答案解析】[解析] 题干中提到了新信息：“发达国家”和“更高的死亡率”，利用这两个重要信息作为答案线索，这样发现文章中只在第3段捉到了“The plan remains very likely to cause controversy since it involves making use of a virus which has caused more than 22 million deaths around the world in the past two decades．”而并没有提到具体什么国家，也没有“发达国家”或“发展中国家”这样的字眼，所以判断该题为“没提到”。