题目

听下面一段较长对话，回答以下小题。【1】What are the speakers talking aboutA. Fitness plan B. Diet plan C. Work plan【2】What does the man prefer?A. Chicken. B. Turkey. C. Hamburger【3】How often will the man eat fruit?A. Twice a day B. Three times a day. C. Four times a day. 答案：【答案】【1】 A 【2】 C 【3】 C 【解析】此题为听力题，解析略。【1】此题为听力题，解析略。【2】此题为听力题，解析略。【3】此题为听力题，解析略。已知正方体ABCD-A1B1C1D1，O是底ABCD对角线的交点．求证：（1）C1O∥面AB1D1；（2）面BDC1∥面AB1D1．