选做题：小文章改错。
Fish are beautiful. Raising fish is a art. Fish should be kept in a glass container where contains water and
a layer of sands. Water plants should be put in them. When winter come, the container should be put where
is warm. The water should be kept in the temperature of 20℃. The fish should be fed on regularly every day,
and the water should be changed once a week. By doing so people become patient or develop a good habit of
keeping regularly hours.
_________________________________________________________________________________________