题目

阅读理解 What is your favorite English letter? Many of you may say QQ. Why? Because so many of you chat with your friends on QQ. What do you like about QQ? What do you talk about? The CCTV reporter, Miss Wang, interviews three kids. Let's listen to what they say.     Miss Wang: When do you chat on QQ? What do you talk about?     Lin Yuhan, Xi'an: On weekends.   1    Tang Xuting, Shanghai: At weekends and when I don't have much homework. We exchange test answers and chat.     Yang Yuhang, Dalian: Our class goes online together at 4-6 pm on weekends. We complain about h 已知(x≠0，y≠0，z≠0) 求(1)x∶y∶z；(2)．