Among all the computer pointing devices, touch screen is the most expensive one.（）
People began to rely on the mouse for routine computer tasks ever since Stanford University invented computer mouse.（）
According to the author, general computer users need not know how the computer mouse was invented.（）
The computer mouse derives its name from the cable that goes out its body, which looks like the tail of a mouse.（）
LED technology is widely used in various fields all over the world.（）
The key components of a computer mouse are the two LED.（）
