题目

－ Will's already back from the charity walk, _ he'?－______. Now he's taking a rest in the next room.A．hasn't; YesB．has; NoC．isn't; YesD．is he; No 答案：C解析: 略下列的估测，最接近实际的是A.2个鸡蛋的重力约为0.1NB.普通课桌的高度约为80dmC.人正常步行的速度约为5m/sD.人体的密度大约是1.0×103kg/m3