以下关于Visual Basic程序模块的描述正确的是

A．标准模块中的所有过程可以在整个工程文件的范围内被调用

B．窗体模块Form1中的过程可以调用其他窗体中被声明为Public的通用过程

C．如果工程文件中包含sub Main过程，则运行该工程文件时，一定先执行sub Main过程

D．如果工程文件中不包含sub Main过程，则程序从第一个创建的窗体开始运行

Virtual reality (or VR (1) ) is kind of a buzzword these days in computer graphics.VR is artificial reality created by a computer that is so enveloping that it is perceived by the mind as being truly real.VR exists in many (2) .A traditional view of virtual reality uses headsets and data gloves.The headset serves as the eyes and ears to your virtual world,projecting sights and sounds generated by the computer.The data glove becomes your hand,enabling you to interact with this (3) world.As you move your head around,the computer will track your motion and display the right image.VR is the most demanding (4) for computer graphics,requiring hardware and software capable of supporting realtime 3D (5) .

A．for certain

B．for any sake

C．for all

D．for short