Are these sentences grammatically correct?

1) I don’t like him because he had a bad temper, and he polluted the stream.

2) I think the biggest success of World Watch was to encourage people to recycle materials.

3) I think the best thing I will receive is a World Watch Wrist Watch because it is something unique which you can’t buy from shops.

4)The leaflet is good because it makes people aware about the importance to safeguard the environment. It also tells people what to do to make the world a better place.

5) We can all help to make the world a better place by recycling materials, protecting world’s wildlife and reducing traffic pollution in our cities