影响射线照相影像质量因素的胶片衬度相关因素包括（）
A、胶片类型
B、显影处理工艺
C、底片黑度
D、增感屏类型
E、以上都是
参考答案：E
Your company CEO just sent you an E-mail asking you to make a presentation on your project，which has been in progress for 18 months，to all identified internal and external stakeholders．He scheduled the presentation for next Monday．You expect more than 50 people to attend．The first step in preparing the presentation is to______．
A．define the audience
B．determine the Objective
C．decide on the general form of the presentation
D．plan a presentation strategy
