题目

读一读,从右栏里找出答语，将序号填在括号内。① When is your birthday?A. I often watch TV.② What do you do on the weekend ?B. It is in May.③ Is Christmas in July? C. No, it isn't.④ Which season do you like best? D. Cool.⑤ Let's go to the Great Wall. E. Winter. 答案：【1】B【2】A【3】C【4】E【5】D图中的等腰直角三角形表示三棱镜，光线垂直于一个面入射，在底面上发生全反射，由此看出棱镜的折射率可能是（　　）A．1.7B．1.8C．1.5D．1.36