Computers can injure you. Most other injuries happen suddenl

Computers can injure you. Most other injuries happen suddenly. For example, if you fall off a bike and break your arms, it happens very quickly. But computer injuries happen slowly.
You probably know how to ride a bike safely. Now learn to use a computer safely.
Your eyes--Too much light can injure your eyes, so never sit too close to a computer screen. Your eyes should be at least 50 centimeters (厘米) from the screen. Remember to look away from it sometimes. This gives your eyes a rest.
When you use a computer, the window should be on your left or your right. If it is behind you, the light will reflect (反射) on the screen. If the window is in front of you, the sun and the screen will both shine into your eyes.
Your hands--Hand injuries can happen because the hands are moved in the same way hundreds of times. If you use a keyboard for a long time, follow this rule: Stop sometimes and exercise your hands and fingers in different ways.
Your back--Some people sit for many hours in front of a computer. If you sit in the wrong way, you can injure your back and your neck. So you should sit with your back straight. The top part of the screen should be in front of your eyes. If you are sitting for a long time, get up every 30 minutes and exercise your arms, legs and neck.
Enjoy your computer, but use it safely.
小题1:How many kinds of computer injuries are mentioned in this passage?

A．One.

B．Two

C．Three.

D．Four.

小题2:A computer screen may injure your eyes if .

A．you sit 60 centimeters away

B．you remember to look away

C．your eyes are too close to it

D．the window is on your left or right

小题3:Your eyes and hands will be safe if _________.

A．you work near a window

B．you often take rests from working

C．you use a keyboard for a long time

D．the window is behind you

小题4:Which sentence is NOT true according to this passage?

A．You should sit with your back straight while you work on a computer.

B．Staying in front of a computer too long may injure your eyes.

C．When you work on a computer, your hands almost move in the same way.

D．The writer thinks that computer is bad for your health.

小题5:What would be the best title for the text?

A．How to protect your eyes

B．How to protect your hands

C．How to use a computer safely

D．How to protect your back