阅读下面短文，在空格处填入一个适当的词或者使用括号中词语的正确形式填空。

    Animals are helpful. And animals are very important part of the world. October 4 is World Animal Day. This is a great chance to celebrate our lovely (friend).

    They help keep nature on the right track. For example, bees move pollen (花粉) and seeds among plants. If they don't do so, things may stop (grow), and we would have no food eat.

    Animals can also tell (we) about our past. Studies on monkeys show us human evolution (进化).

    We also keep animals pets. They give us support (支持) and make us happy. So we (not) get lonely.

    We need animals in our (life), and we can't live (with) them. So always show respect (尊敬) and love (to) them.