阅读理解。 For Americans, a mosquito bite is an itchy (发痒的) bother. But for many in Africa, a tiny bite can be deadly. One million people die each year of malaria, a disease spread by infected mosquitoes. Most of these people live in Africa, and are under age 5. Malaria can be prevented and treated. However, many African nations don't have the funds (基金) to fight it. Nothing but Nets (NBN) hopes to change that. The United Nations Foundation created the campaign in 2006. The aim is to prevent malaria by covering sleeping areas with nets. Hanging bed nets treated with insecticide (杀虫剂) is the simplest way to stop mosquitoes from biting at night. The chemicals last four to five years. For $10, anyone can send a net to Africa and help save a life. So far, NBN has raised $19 million and delivered 700 000 nets to seven countries. Families are taught how to use the nets. Kids also get vaccines (疫苗) and vitamins. 'Women line up for miles to get the medicine for their kids,' says NBN director Elizabeth McKee Gore. 'They understand the importance.' So do kids in this country. 'They get so excited thinking of ways to raise money,' says NBN spokesperson and basketball star Ruth Riley. NBN's biggest fund-raiser is Katherine Commale, a seven-year-old girl. She's been spreading the information about bed nets for the past two years. To show how they work, she and her brother made a video. 'We teach that bed nets can save lives,' she said. Katherine has raised $ 42 000 for NBN. 'She just wants those who need a net to have one,' says her morn, Lynda. 'It's pretty simple to her.' To find out how you can help, visit nothingbutnets, net. 1. Why don't those African nations do something about malaria? A. Because the disease cannot be prevented and treated. B. Because those nations don't know what to do with it. C. Because those nations don't have the money for it. D. Because nothing but nets can change it. 2. The underlined word 'they' here refers to '_____'. A. bed nets B. fund-raisers C. families who are taught to use the nets D. Katherine and her brother 3. How does Katherine Commale raise money? A. By visiting nothingbutnets, net. B. By spreading information about bed nets. C. By teaching people how to use bed nets. D. By making video programs.