第21题: [单项选择]A scientist interested in adding to our general knowledge about oxygen would probably call his approach ______. A. applied science B. agriculture science C. pure science D. environmental science 参考答案:C 答案解析:第四段中讲到“aimed at satisfying curiosity,is referred to as pure science.”,即旨在满足求知欲的科学方法叫做纯科学,因此,增加我们在氧气方