Read the following passage and choose the item (a, b, c, or d)that best answers each of the questions about it.
- Place your computer on a flat table or desk.
- Make sure your chair is a comfortable height.
- Use a screen to protect you from dangerous X-rays.
- Not place it near a fire or the central heating.
- Not leave your computer in the sun.
- Not put liquids on the computer; they may get inside.
- Not eat while you’re working; food can fall into the keyboar
- Clean the computer and dust it regularly.
- Keep the floppy disks clean and in their box.
- Always switch off the computer and the screen when you finish.
You_____ eat while you are working.
shouldn’t don’t have to needn’t to all are