题目

目前，制约我国经济、社会发展的关键因素和首要问题是 A．环境问题        B．粮食问题        C．资源问题        D．人口问题 答案：DLights are out. The concert will begin soon. The fans are holding their breath for their favorite star’s _______.A.appearanceB.influenceC.experienceD.silence