If you go out to the fields at night in spring or summer, you can hear frogs singing   (happy) here and there. It seems as if they were performing a field group singing.

The frog is a good and useful creature that benefits human beings. They can catch fast-moving (insect). Each frog eats a large number of pests that are harmful to crops. This little creature is regarded "the natural enemy of pests".

But now frogs (get) fewer and fewer. This is because they are killed and put the table as a delicious dish by their chief enemy—human beings. It is a shameless and cruel act, isn't it?

The cause that is  (responsibility) for the rapid reduction of frogs is that farmers use insect killers to kill pests and frogs get killed as a result of drinking poisoned water while  (eat) poison-killed insects.

Something must be done as soon as possible (save) frogs. If we don't punish those sell and kill frogs to make money, then one day all of us (punish) by nature for failing to keep them.