高中英語語法填空:短文題型能力練習(xí) Test 30

高中英語語法填空:短文題型能力練習(xí) Test 30

Scientists are working on ways to stop a disease that threatens one-fifth of the world's population. Over 120 million people 　61　 (infect) with lymphatic filariasis, also known as elephantiasis. The disease is found mainly in Southeast Asia and Africa. It affects the lymphatic system which is 　62　 major part of the body's natural defense for fighting disease.

Elephantiasis can cause swelling or enlargement of skin and tissue. The cause is a tiny worm 　63　 enters and lives in lymphatic tubes for six to eight years.

Scientists say they have been able to demonstrate that the most common cause of elephantiasis can be stopped. They 　64　 (urge) those at risk to sleep under nets treated 　65　 chemicals that kill a common insect — the mosquitoes.

Lisa Reimer teaches at the Liverpool School of Tropical Medicine. She says she was surprised at how effective anti-malaria bed nets 　66　 (cover) with insecticide could be at fighting the disease.

Doctors normally use drugs to fight the disease. Ms Reimer says doctors in Papua New Guinea gave the drugs to people of five villages. She says this treatment 　67　 (near) ended the threat from the worm to humans, but the drugs didn't stop the threat from mosquitoes.

The treated nets block female mosquitoes from 　68　 (secure) blood, which is necessary for them to reproduce. The insecticide also cuts the life of the insects in half.

“ 　69　 we can reduce mosquito-biting rates then we're able to increase the thresholds below which the disease prevalence will move to zero. So by controlling mosquitoes we're making the targets for the mass drug administration more 　70　 (obtain). ”