单选题
Antibiotic Resistance Clue Found

US scientists have uncovered a defence mechanism in bacteria that allows them to fend off the threat of antibiotics.
It is hoped the findings could help researchers boost the effectiveness of existing treatments.
The study published in Science found that nitric oxide produced by the bacteria eliminates some key effects of a wide range of antibiotics.
One UK expert said inhibiting nitric oxide synthesis could be an important advance for tackling tricky infections.
Antibiotic resistance, for example with MRSA, is a growing problem and experts have long warned of the need to develop new treatments. The latest research, done by a team at New York University, showed that in bacteria the production of nitric oxide—a small molecule made up of one nitrogen and one oxygen atom—increased their resistance to antibiotics.
They found the enzymes responsible for producing nitric oxide were activated specifically in response to the presence of the antibiotics. They also showed that nitric oxide alleviates damage caused by the drugs as well as helping to neutralise many of the toxic compounds within the antibiotic.
The researchers then showed that eliminating nitric oxide production in the bacteria allowed the antibiotics to work at lower, less toxic doses.
More effective
Study leader, Dr Evgeny Nudler, said developing new medicines to fight antibiotic resistance, such as that seen with MRSA is a" huge hurdle".
"Here, we have a short cut, where we don't have to invent new antibiotics. "Instead we can enhance the activity of well - established ones, making them more effective at lower doses.
Dr Matthew Dryden, consultant in microbiology and communicable disease at Royal Hampshire County Hospital and general secretary of the British Society for Antimicrobial Chemotherapy, said if the enzyme which creates nitric oxide could be inhibited, it could suppress the ability of the bacteria to counteract antibiotics.
"This would be a useful therapeutic advance, especially as we are running out of new classes of antibiotics and there is less antibiotic development in general. /

单选题 What is right about nitric oxide?
【正确答案】 B
【答案解析】考查特定概念定位到文章原句nitric oxide produced by the bacteria…nitric oxide-a small molecule made up of one nitrogen and one oxygen atom，nitric oxide是由细菌产生的，由一个原子和氧原子构成的分子。选项B正确地解释了其分子结构和来源，故是正确的。
单选题 How does nitric oxide reduce the effect of antibiotics?
【正确答案】 A
【答案解析】考查具体事情发生的方式定位到文章原句…showed that nitric oxide alleviates damage caused by the drugs as well as helping to neutralize many of the toxic compounds within the antibiotic，nitric oxide会消除药物对细菌感染的破坏力，也中和了抗生素的毒性化合物，可见选项A认为通过消除了细菌对感染的破坏力来降低抗生素的作用是正确的。选项B认为中和了细菌自身带有的毒性化合物，是不正确的。
单选题 What is the meaning of" huge hurdle"?
【正确答案】 B
【答案解析】考查特定词汇的理解hurdle原意是跳栏，一种体育项目，在这里通过上下文可以理解发展新的有很强的耐抗生素抗药性的药物是很难的，故选项B是正确的。选项C意为很轻易的事情，不合文意。
单选题 What is not mentioned by Dr Evgeny Nudle?
【正确答案】 D
【答案解析】考查文中人物的观点定位到文章原句we don't have to invent new antibiotics．Instead we can enhance the activity of well-established ones，making them more effective at lower doses．我们并不一定要发明新的抗生素。我们可增强已有药物的效力，使更低计量的药物有更好的效力。选项D认为nitric oxide是重大发现，这并没有被教授提及，故应选择D。
单选题 According to Dr Matthew Dryden, what is essential to suppress the bacteria resistance to antibiotics.
【正确答案】 A
【答案解析】考查具体事物的组成部分if the enzyme which creates nitric oxide could be inhibited．it could suppress the ability of the bacteria to counteract antibiotics．如果制造nitric oxide的酶可以被阻止，那就可以抑制细菌抗生素的抗药性，选项A认为阻止制造nitric oxide的酶，是合文意的，故选择A。选项B认为阻止由nitric oxide制造的酶，是不合文意的。