题目

C Wikipedia was founded as a branch of Nupedia, a now-abandoned project to produce a free encyclopedia (百科全书). Nupedia required highly qualified contributors, but the writing of articles was slow. During 2000, Jimmy Wales, founder of Nupedia, and Larry Sanger, whom Wales had employed to work on the project, discussed ways of supplementing (补充) Nupedia with a more open project. Multiple sources are suggested for the idea that a wiki might allow members of the public to contribute material, and Nupedia’s first wiki went online on January 10. There was considerable resistance on the当一个人站在坚硬的水泥地面上时，水泥地面（ ）A．发生了弹性形变，对人施加了弹力的作用B．发生了弹性形变，对人施加了重力的作用C．没有发生弹性形变，因为地面太坚硬了D．没有发生弹性形变，因为人太轻了