【正确答案】 A

【答案解析】[听力原文]
Researchers in the United States are exploring a possible way to control malaria. They are developing insects resistant to the disease.
More than three million people become infected with malaria each year. The disease kills at least one million people every year. Malaria is found in Africa, Asia, the Middle East and South America.
Malaria parasites enter a person's blood through the bite of a very small insect-the mosquito. The malaria parasites travel to the liver. The organisms grow and divide there. After a week or two, the parasites invade red blood cells and reproduce thousands of times. They cause a person's body temperature to rise. They also may destroy major organs. People with malaria may suffer kidney failure or loss of red blood cells.
People die from malaria because they are not treated or treatment is delayed. Different drugs can prevent the parasites from developing in the body. But experts still say the best way to prevent the disease is not to be bitten by a mosquito.
That could change in the future. Research scientists at The Johns Hopkins University have created mosquitoes that cannot spread the malaria parasites. Computer studies show that such insects are needed to replace mosquitoes in the wild if malaria control is to succeed. The researchers reported their findings in the Proceedings of the National Academy of Sciences.

【正确答案】 A

【正确答案】 B