如图所示梯形玻璃砖ABCD，∠A=45°，∠B=105°，AB边长为L．一束平行于AB边的光线由AD边入射，经折射后在AB边中点发生全反射，直接射到BC边，且与BC边成45°角射出玻璃砖．求：

①玻璃砖的折射率；

②光线在玻璃砖内传播的时间．

下列关于生命系统的叙述，错误的是：

函数y=2+log₂x（x≥1）的值域为（   ）

任务型阅读 
    My friend, Tom lives a happy life.（1）He usually gets up at 6:00 . Then he goes for a walk. At 7:00 he comes back. He brushes his teeth and takes a shower. （2） Then he eats breakfast. After breakfast, he goes shopping（购物）with his friends. （3）他大约十点半到家。And he cooks lunch. After lunch, he goes to the club. He reads books and plays chess. He eats dinner at home at 6:00 pm. （4）           the evening he likes watching TV. At around 9:00 pm he goes to bed.
根据短文内容，完成下列任务

下列不能传播艾滋病的途径是（      ）