题目

设全集U=R，集合A=，B=，则（ ）A. B.C. D. 答案：【答案】B【解析】由集合求出，利用交集的定义进行运算得出答案．集合A=，则故选：BTo protect the environment is __________to take care of our lives.A.importantB.as important asC.more importantD.the most important