题目

我国古代数学名著《九章算术》中有这样一些数学用语，“堑堵”意指底面为直角三角形，且侧棱垂直于底面的三棱柱，而“阳马”指底面为矩形且有一侧棱垂直于底面的四棱锥.现有一如图所示的“堑堵”，，若，当“阳马”体积最大时，则“堑堵”的表面积为（ ）A. B. C. D. 答案：【答案】B【解析】设，则由题意“阳马”的体积是，当且仅当时取等号，则“斩堵”的表面积为，应选答案B。阅读理解 1．If you get into BDU, you can ________. [　　] A．know everything in China B．get the most important business information in the world C．get the information of the latest business activities taking place in China D．get all the information in China Daily 2．This ad will be very helpful to ________. [　　] A．foreign business people B．foreign travelers C．Chinese people D．China Daily reporters 3．To get the information from BDU every day, you must ________. [　　] A．understand Chinese B．know something about the mouse C．know how to operate a computer D．how to use a fax machine 4．If you have www.chinadaily.com.cn./bdu, you can get in touch with BDU by ________. [　　] A．telephone B．fax C．E-mail D．internet