Пояснения тут излишни, достаточно понимать смысл предложения)
1)Tne elephant is the ... (big) lang animal. =biggest
2)Monkeys are...(sociable) than giraffes. =more sociable
3)These baby monkeys are... (curious) than those ones. =more curious
4)A dog is a man"s...(good) friends.=best
5)I think dolphines are the ...(clever) animals in the world. =cleverest
6)Horses are ...(beautiful) than camels.= more
beautiful