Пожалуйста помогите с заданиями

17. fast - faster - the fastest
good - better - the best
weak - weaker - the weakest
hard - harder - the hardest
happy - happier - the happiest
bad - worse - the worst
short - shorter - the shortest
small - smaller - the smallest
young - younger - the youngest
large - larger - the largest
high - higher - the highest
short - shorter - the shortest
clever - cleverer - the cleverest
18. 
1. Amy is better at PE than me
2. Superman is stronger than Batman
3. The cheetar is the fastest animal of all
4. Katie is the best singer in my class