题目

 He was wearing a pair of sunglasses and I didn’t _____him at first. A. advise              B. promise                C. recognise      D. hear 答案：C已知⊙O的半径为5cm，点A为直线L上一点，且OA=5cm，则⊙O与L的位置关系是（　　）A．相交B．相切C．相切或相交D．相离