题目

为使雨水尽快离开房屋的屋顶面，屋顶的倾角设计必须合理。某房屋示意图如图所示，设屋顶面光滑，倾角为θ，雨水由静止开始沿屋顶面向下流动，则理想的倾角θ为（） A . 30° B . 45° C . 60° D . 75° 答案：B---Journalists have to work very quickly in order to       . ---I know. I like that. It’s very challenging. A．avoid lose their job B．avoid firing C．avoid being fired D．avoid to be fired