1 Plants must be watered by people.
2 People should be cleaned up their rubbish.
3 Rubbish shouldn't be settled in rivers or lakes.
4 Trees coudn't had the opposit effect in ecology.
5 Animals shouldn't suffered from ecological problems.
6 People could refused to use gas cylinders in cars.
1 Plants must be watered by people.
2 People should be cleaned up their rubbish.
3 Rubbish shouldn't be settled in rivers or lakes.
4 Trees coudn't had the opposit effect in ecology.
5 Animals shouldn't suffered from ecological problems.
6 People could refused to use gas cylinders in cars.