Put the adjectives in brackets into the comparative or the superlative.
1.i'm (short) student in my class.
2.tom is (thin) gred.
3.he's (energetic) person i know.
4. claire is (friendly) her sister.
5.my brother is (good) at windsurfing than i am.

  dolphins are cleverer than whales.  horses are taller than dogs.  cats are bigger than mice.  tigers are faster than dogs.  snakers are longer than lizards.

in my hometown i have a lot of eco-problems. i think the main problem is air pollution. when air is polluted it changes the climate and damages animals' and our health. when people throw litter in the river they cause the second problem - water pollution. polluted water hurts water animals. when we leave litter in the forests, nature is damaged. a lot of people don't recycle paper, they cut down trees to make new paper. when trees are broken or cut down, birds are disturbed. land, air and water are important for flowers, trees, animals and people. we must protect our planet and try to save it!