* before and after a meal

Careful people can avoid illness

this was my English exam question:-
write a paragraph of seven sentences about (Careful people can avoid illness)
that is what i wrote:

It's now clear that our health plays a very important role in our life and we can't do without it.From this point As a result of this, careful people spare no effort to avoid illness.
To avoid illness we should remember some rules. First of all we should always wash our hands ofter and before  a meal. We should wash more often in hot weather or when we have been to a the gym.
We mustn't eat food that smiles smells bad as it may be poisonous. We should always cover our food so that flies can't pass their germs on to it. We should boil tap water before drinking it to kill any germs. We must try not to eat food from cans as it may be bad.
If we do so,we will have a good health and never suffer from illness.

any mistakes?