Complete the sentences with the given words in their proper forms（用所给单词的适当形式填空）
【小题1】Lily is a ____________ (friend) girl.
【小题2】The horses are ___________(help) to the farmers.
【小题3】Water ____________ (pollute) is bad for us.
【小题4】Today is my father's ___________ (fifty) birthday.
【小题5】We must eat ____________ (many) vegetables and __________ (little) meat than before.
【小题6】He has ___________ (few) friends than I.
【小题7】Look! How __________(luck) they are! They won the game.