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Mosquitoes (蚊子) carry malaria (疟疾), which kills thousands of people each year. Now some researchers are trying to use genetic engineering (基因工程) to make them into partners in the fight against the disease.

For years, public health officials have tried to limit the disease by controlling mosquito populations. “But that approach is short-term,” says Anthony James, a professor of biology and genetics at the University of California, Irvine, “because mosquitoes are very tough little insects, and their populations can quickly increase.”   

Therefore, James and his colleagues want to try a different approach: making mosquitoes themselves into malaria-fighting warriors (勇士), which is completely different from traditional ways of controlling malaria.

To understand how it works, it helps to understand the life cycle of malaria. The malaria pathogen (病原体) is a parasite (寄生虫) that grow inside humans. It’s passed via mosquitoes that move from person to person, sucking blood. “If we can make the mosquitoes difficult for the pathogens to survive, we can wipe out the disease,” he says. But making mosquitoes uninviting to malaria is a Herculean task.

To solve the problem, the team used a gene-editing technique called CRISPR. They stated with genes from mice, whose immune systems (免疫系统) do fight human malaria, engineered those genes, and then gave them to the mosquitoes.

It turned out the gene-edited mosquitoes worked very well. They reduced the number of parasites in the mosquito before they were passed to a human host.

James’ team are now working on planning a field trial, which he hopes could be done on an island or in another isolated location.

       But genetically changing wild animals does not sit well with environmentalists. “There’s no need to engineer a mosquito,” says Dana Perls, senior program manager for the emerging technology program at the non-profit Friends of the Earth. Perls points out that natural ways to reduce malaria appear to be showing promise, as does a new vaccine (疫苗) against the disease. “Why take unnecessary risks and use mosquitoes that can’t be controlled once sent into the wild?” she asks.
1．What can we know from the second and third paragraphs?

A．Mosquitoes can reproduce quickly.

B．Mosquitoes can be easily controlled.

C．Mosquitoes have killed thousands of people.

D．Mosquitoes have been used to fight against malaria.

2．What does the underlined phrase “a Herculean task” in Para. 4 mean?

A．A great comfort.

B．A tough job.

C．A narrow escape.

D．A key factor.

3．What is environmentalists’ attitude towards this new approach?

A．Unconcerned

B．Supporting.

C．Negative.

D．Positive

4．What is the best title for the text?

A．Preventing Malaria with a New Vaccine

B．Curing Malaria with Gene-edited Mosquitoes

C．Limiting Malaria by Controlling Mosquito Populations

D．Controlling Malaria by Engineering Mosquitoes’ Genes