题目

某人用直径为80厘米的铁环，绕操场滚动一周，若铁环刚好滚动80圈，求操场的周长是多少米? 答案：解：解：d=80cm=0.8m S=nc=nπd=80圈×3.14 ×0.8m/圈=200.96mLi was beaten in the contest, ______ had been expected.A.whatB.thatC.asD.who