题目

世界上第一次把圆周率的数值，精确到小数点以后第七位的数学家是（ ） A . 刘歆 B . 刘徽 C . 张衡 D . 祖冲之 答案：D—I’m trying to find yesterday’s newspaper．Have you seen it?—I’m afraid that I ______ it away．I thought you had finished reading it．A.threwB.had thrownC.throwD.will throw