题目

下列生产工具发明的先后顺序，排列正确的是（   ） A．①②③④         B．②①③④         C．②①④③        D．③①②④ 答案：CPerhaps the best sign of _____ computer and internet use pushes up demand for paper comes from the high-tech industry itself.A．howB．whatC．whyD．that