题目

已知是半径为1的⊙的一条弦，且．以弦为一边在⊙内作正△，点为⊙上不同于点A的一点，且，的延长线交⊙于点，则的长为（  ▲  ）．A．       B．1     C．      D．   答案：B解析:略 【小题1】I am poor in speaking English because I don’t have the correct _____.【小题2】In the past few years, we have _____in saving thousands of people in danger.【小题3】I think they have gone to the airport to _____their daughter _____.【小题4】Many people are looking forward to ______ in big cities.【小题5】His uncle has been ________ for three years.【小题6】This is the __________ letter she has received this week.【小题7】 We are often ________to speak more English by our English teacher.【小题8】She never feels __________ and tired in the class 【小题9】The careful girl found ten _____________ between the two pictures.【小题10】Guangzhou is a big city in the ________ part of China.