题目

在棱长为1的正方体上，分别用过共顶点的三条棱中点的平面截该正方体,则截去8个三棱锥后,剩下的凸多面体的体积是                                       （    ） A.           B.              C.                D. 答案：D Come and enjoy yourselves here!Nowadays, people have a lot of pressure in their daily life, and everyone seems to have no time to stay with their friends and family. Maybe you want to have a change, either hang out with friends or just go out for a movie. Perhaps you can't find a satisfying solution. Now we provide you a great chance to spend some wonderful time with your loved ones. Join us for an evening full of humor, history and horror in the streets of Old Glasgow.Walking Tours of GlasgowTime: From April 15th to October 7th Historic Glasgow 2：00 p．m.Gruesome Glasgow 3：30 p．m.Ghosts and Ghouls 5：00 p．m. (weekday only)All tours leave from George Square. Each tour lasts 30 minutes.Ticket Price：Adults: ￡5.00　Teenagers: 10% offChildren (under 12): 20% offFamily (2 adults & 2 children): ￡13.50More information：Fax/Tel.: 0516－77769Web: http：//www.mercattours.comI believe you will have fun joining all the activities. Invite some of your friends before it's too late. We are here waiting for you!【1】If an adult, 2 teenagers and a 10－year－old child want to have a tour there, how much should they pay?A.￡17.B.￡18.C.￡19.D.￡20.【2】If people want to know more information, what CAN NOT they do?A.Make a phone call.B.Send a fax.C.Visit their website.D.Send an e-mail.【3】What can we infer from the given information?A.You can join the tours of Glasgow in any month you like.B.Only Children can have discount.C.Some tours leave from George Square.D.There will be activities at night in the streets of Old Glasgow.