2012年11月21日星期三

Microorganisms can be harmful too

Here are some harmful effects of microorganisms.

  • Some microorganisms that enter the body can cause illness.
  • Eating food contaminated with microorganisms can cause food poisoning.
  • Bacteria act on the food remains betwen the teeth. This produces acid which causes tooth decay.
  • Food turns bad because of bacteria and fungi
 

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