题目

In the future, care for the environment will become very important as earth’s natural resources ___________.A.run out B.run over C.use up D.use out 答案：【答案】A【解析】考查动词短语辨析。句意:未来，随着地球上资源的耗尽，对环境的关心变得越来越重要。A. run out耗尽，不及物动词，主语是时间、金钱、食物等无生命名词；B. run over碾过；C. use up及物动词，耗尽，主语为人，相当于run out of，表示已经用完；D. use out耗尽，强调动作。故选A。13．求曲线y=x2与y2=x所围成封闭图形的面积，其中正确的是（　　）A．S=${∫}_{0}^{1}$（$\sqrt{x}$-x2）dxB．S=${∫}_{0}^{1}$（y2-$\sqrt{x}$）dxC．S=${∫}_{0}^{1}$（x2-$\sqrt{x}$）dxD．S=${∫}_{0}^{2}$（$\sqrt{y}$-y2）dy