阅读理解。 Do you know that fish comes out of eggs when it is born(出生)? After the little fish comes out of the egg, it eats the food in the egg. When it is big, it leaves the egg. It swims in the water. You can see the eyes and nose. Its ears are hidden(藏) in the head. Some fishes eat other small fishes. Some fishes have small mouths and teeth and they often eat plants(植物). 根据短文内容用适当的单词填空. The fish is in an (1)__________ before it is born. The fish eat the (2)_________ in the egg after they come out of the egg. When the fish is big, it doesn't (3)__________ in the egg any more. In fact(事实上), a fish (4)_______ ears, but they are hidden in the head. (5)________ big fishes eat small fishes.