题目

阅读理解，阅读下面短文，从每题所给的A、B、C、D四个选项中，选出最佳选项。 Katherine Com male is an 11-year-old girl from Pennsylvania. At the age of five she began raising money to buy nets for children in Africa to help stop the spread of malaria(疟疾). When she was five, Katherine learnt about malaria in Africa. She learnt that every 30 seconds a child died from this disease. She, also learnt that people wouldn’t get that disease if they had enough bed nets. “I was really sad to learn that a child died every half a minute because of malaria.” SaKW?h是________的单位，2KW?h等于________J．