题目

如图，△ABC内接于⊙O，若sin∠BAC=，BC=2，则⊙O的半径为（ ）A. 3 B. 6 C. 4 D. 2 答案：【答案】A【解析】连接OC并延长交圆与,连接,可得∠A=∠,由sin∠BAC=，BC=2，可得⊙ O的半径.解：如图：连接OC并延长交圆与,连接,可得∠A=∠,可得sin∠===,可得=,即圆的直径为，圆的半径为，故选A. 听力(共两节，满分30分) 第一节：(共5小题，每小题1.5分，满分7.5分) 听下面5段对话。每段对话后有一个小题，从题中所给的A、B、C三个选项中选出最佳选项。听完每段对话后，你都有10秒钟的时间来回答有关小题和阅读下一小题。每段对话仅读一遍。 1．Where does the conversation probably take place? A．In the hospital B．At the hotel C．At the airport 2．Who likes the concert most? A．The man B．Helen and Bill C．Helen,Bill and the man 3．How much time does the woman have to get ready? A．About 10 minutes B．About 15 minutes C．About 30 minutes 4．What do we know about the man? A．He is ready to help the woman． B．He wanted to ask some questions first． C．He refused to lend the money． 5．What should Miss Lee do according to the man? A．She should prove herself to others first． B．She should talk to the director． C．She should try to improve first． 第二节：(共15小题；每小题1.5分，满分22.5分) 听下面5段对话或独白。每段对话或独白后有几个小题，从题中所给的A、B、C三个选项中选出最佳选项。听每段对话或独白前，你将有时间阅读各个小题，每小题5秒钟；听完后，各小题将给出5秒钟的作答时间。每段对话或独白读两遍。 听第6段材料，回答第6至8题。 6．Where does the woman live? A．Nearby B．In the restaurant C．In the junior school 7．What’s the woman’s job? A．Waitress B．Teacher C．Headmaster 8．What’s the man’s opinion of school children? A．They’re hard to control． B．They like to listen to the teachers． C．It’s quite easy to teach them． 听第7段材料，回答第9至11题。 9．What has happened to the man? A．His house was broken into． B．He has locked himself out． C．He forgot to lock the front door． 10．When did he lock all the windows? A．On Saturday B．On Sunday C．On Friday 11．What is the woman most probably going to do? A．Look round B．Talk to others C．Ask more questions 听第8段材料，回答第12至14题。 12．Where does the conversation take place? A．At a computer store B．At a garage C．At a hotel 13．What service will the woman get at last? A．Having her computer fixed． B．Getting a brand new computer． C．Renting a WIFI(无线局域网)computer． 14．What can we learn from the conversation? A．The woman uses computers a lot． B．The woman works at the business center． C．The rent is 5 yuan per hour． 听第9段材料，回答第15至17题。 15．Which is true about Robert and Betty? A．They are classmates． B．They work together． C．They have never met each other． 16．Why are they here? A．To find a teacher． B．To learn art． C．To find a room． 17．What can we learn about the man from the conversation? A．He is humorous and popular． B．He is friendly and helpful． C．He is polite and happy． 听第10段材料，回答第18至20题。 18．What is the best way to shop for the holiday gifts? A．To find out all the cheapest things． B．To spend as much money as you can． C．To compare price and find out the most appropriate． 19．Which of the following is not recommended for gift-giving? A．Making a list． B．Thinking about the money you can spend． C．Dividing the money equally． 20．What is the best gift of all? A．A homemade gift． B．The most expensive gift． C．The most delicate gift．