题目

All the scientific evidence ___ that increasing use of chemicals in farming ____ damaging our health. A. show; are                 B. shows; are C. shows; is                 D. show; is 答案：C测得某物质中只含一种元素，关于该物质的分类错误的是（ ）A.可能是单质B.可能是化合物C.可能是纯净物D.可能是混合物