help is urgent please

potatoes are cheaper than strawberries.( 
Spain is bigger than Portugal.
My bedroom is cleaner than my sister's bedroom........ cheap/cheaper= moins cher
I don't like sciences very much, I think it is more difficult than English
My brother is more stupid than me. He always wants to win
A sheep is heavier than a monkey.  (heavy/heavier = lourd)
I think chocolate ice-creams are better than vanilla ice-cream. good/better
A ferrari is faster than a Renault clio.  (fast/faster = rapide)
The Empire State Building in Manhattan is higher than the Eiffel tower in Paris
05/20 is worse than 15/20    (bad / worse = mauvais/ pire que)