I have lost my dictionary. I have to buy 发布时间:2017-05-18 10:57 │ 来源:www.tikuol.com 题型:选择题 问题: I have lost my dictionary. I have to buy a new _______.A.itB.thatC.oneD.this
题型:选择题 I fell in love _______ the beautiful city of Ningbo while I was _______ vacation there. [ ]A. on; with B. to; in C. to; for D. with; on 查看答案
题型:选择题 不定项选择如图所示,空气中有一折射率为的玻璃柱体,其横截面是圆心角为90°、半径为R的扇形OAB。一束平行光平行于横截面,以45°入射角照射到OA 上,OB不透光。若只考虑首次入射到圆弧AB上的光,则AB上有光透出部分的弧长为( )A.πR/6B.πR/4C.πR/3D.2πR/15 查看答案