题目

某几何体是圆锥的一部分，它的三视图如图所示，其中俯视图是个半圆，则该几何体的表面积为（ ）A. B. C. D. 答案：【答案】B【解析】三视图复原可知几何体是圆锥的一半，根据三视图数据，求出几何体的表面积.由题目所给的三视图可得，该几何体为圆锥的一半，那么该几何体的表面积为该圆锥表面积的一半与截面面积的和.又该半圆锥的侧面展开图为扇形，所以侧面积为，底面积为.观察三视图可知，轴截面为边长Ming Ming and Lily are in the same school, 1they are not in the same class. They go 2school on weekdays (工作日，平时). 3school, Ming Ming and Lily often play games with 4friends.Classes begin 5eight in the morning. Now Ming Ming and Lily are in their classrooms. They listen to their 6. Ming Ming studies English in the first class. His teacher talks 7them in English.Lily 8a Chinese class. Her teacher talks 9good articles (文章). They study hard. They love their teachers and they like their 10.1.A.butB.orC.andD.then2.A.atB.forC.toD.on3.A.OnB.FromC.ToD.At4.A.hisB.herC.yourD.their5.A.aboutB.inC.atD.on6.A.friendsB.fatherC.teacherD.teachers7.A.withB.atC.inD.for8.A.hasB.listensC.getsD.sits9.A.atB.aboutC.forD.with10.A.homeB.familyC.schoolD.park