科学家给蚊子喂了减肥药，它们竟然“懒得”咬人了！
By giving mosquitoes diet drugs, they could be prevented from biting humans and spreading deadly diseases, according to a new research. Scientists found that female mosquitoes, which spread the microbes that kill millions of people every year, lose interest in human blood if their appetites are suppressed with the chemicals. The study showed that by using the hormones which make mosquitoes feel full, the insects’ desire for blood can be satisfied.
“We were impressed and amazed that drugs designed to affect human appetite worked perfectly to suppress mosquito appetite,” study author Leslie Vosshall said in a statement. The scientists carried out experiments on female Aedes aegypti mosquitoes, which require human blood for the proteins they need to produce eggs. This species is responsible for spreading yellow fever and Zika virus. The researchers noted, however, that once these mosquitoes fed on human blood and became bloated, their attraction to humans would decline for several days. “It’s like the ultimate Thanskgiving dinner,” said Laura Duvall, a study author.
The scientists gave the mosquitoes a saline solution containing the drugs and found the insects’ appetite and attraction to humans dropped sharply. They measured this by hanging up a nylon stocking previously worn by Duvall for long enough for body odors to be absorbed, and observing whether mosquitoes flew toward it. They also tested the mosquitoes on mice to see whether they would bite a live host.
James Logan, head of the department for disease control at the London School, described the discovery of this potential new technology as “exciting”. “A compound with a novel mode of action that prevents mosquito feeding could help many people if it is effective.” Logan warned, however, that “there is a lot of work to be done before this could be used in the field.”
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1.How could scientists stop the mosquitoes biting humans?
A By spreading deadly diseases to them.
B By controlling their appetites with chemicals.
C By providing them with more blood.
D By changing their hormones.
解析：选B。细节理解题。根据第一段的内容可知通过药物控制蚊子的食欲，让它们有饱腹感，这样就会阻止蚊子叮咬人。故选B。
2.Why do female Aedes aegypti mosquitoes like to feed on human blood?
A They are interested in diet drugs.
B They want to spread diseases like yellow fever.
C They are in need of proteins when producing eggs.
D They are fond of the taste of human blood.
解析：选C。细节理解题。根据第二段第二句The scientists carried out experiments on female Aedes aegypti mosquitoes, which require human blood for the proteins they need to produce eggs.可知这种蚊子需要吸食人血来获取产卵所需的蛋白质。故选C。
3.Which of the following is NOT true according to the passage?
A Leslie Vosshall was excited at what they have found in the experiments.
B The mosquitoes would temporarily lose interest in humans after sucking enough blood.
C The saline solution containing the diet drugs made the mosquitoes’ appetite lose completely.
D A new compound to prevent mosquitoes from biting humans won’t soon be used in practice.
解析：选C。细节理解题。根据第三段第一句The scientists gave the mosquitoes a saline solution containing the drugs and found the insects’ appetite and attraction to humans dropped sharply.可知这种含有药物的盐溶液使蚊子的食欲和对人类的兴趣大大下降，而非使它们完全失去食欲。故选C。
4.What’s James Logan like from the last paragraph?
A He is sensible and careful.
B He is selfish and indifferent.
C He is humorous and funny.
D He is blindly arrogant.
解析：选A。推理判断题。根据最后一段最一句Logan warned, however, that “there is a lot of work to be done before this could be used in the field.” 可知他认为在这种新型化合物运用到实践中之前还有大量的工作要做，由此可推知他是一个对待科学研究严谨认真的人。故选A。