The book was his greatest success; with it he ______. A. arrived B. had arrived C. arrives D. will arrive 答案:A 解析: 此处arrive意为“成名,成功”。如图所示,一轻弹簧上端固定,下端挂一物块甲,甲与乙用一细线相连,且质量相等,在甲、乙间的连线被剪断的瞬间,甲、乙的加速度的大小记作a甲和a乙,那么( )A、a甲=0,a乙=gB、a甲=g,a乙=gC、a甲=0,a乙=0D、a甲=g,a乙=0