目前，海船上操舵装置多采用电力控制，其优点是（）。

①便于遥控并具有较大的应用前景；

②不受船体变形及环境温度的影响；

③工作可靠，维修管理方便。

A.①②

B.②③

C.①③

D.①②③

Virtual reality (or VR (65) 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 (66) .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 (67) world.As you move your head around,the computer will track your motion and display the right image.VR is the most demanding (68) for computer graphics,requiring hardware and software capable of supporting realtime 3D (69) .

68（）

A.App 

B.apply 

C.application 

D.appliance