根据描述,猜猜横线上应该填什么单词?
1.It's a very big animal.It can't jump.It has two long teeth.It's a/an____.
2.It can run very fast.It usually has twored eyes and two long ears.It often eats grass.It is a_____.
3.It can climb trees.It likes eating fruits.It has a long tail.It's a____.
4.It can walk on the land(陆地).But it walks slowly.It also can swim in the water.And in has a long neck.It is a______.
(回答时,标清序号）谢谢