四、Read and fill. 鸭子和蝴蝶是怎样一步步成长起来的呢？请读一读，完成句子。
Duck: Hi, my friend! Look at my babies! They are swimming in the water.
Butterfly: Oh! So cute! Your babies are yellow and they have short tails.
Duck: Yes, I was also small and yellow then. We are all different now.
Butterfly: That’s right. Before I was a caterpillar(毛虫). I ate leaves every day. And I was long and fat. Now I can fly and I see lots of flowers every day.
Duck: Well, I was a duckling(小鸭) before. I swam in the water with my family. And we ate fish. I couldn’t swim fast then. But now I can swim very fast.
Butterfly: And now you are white and look beautiful!
1. Duck was and then.
2. Before, Butterfly was a and caterpillar.
3. Now Butterfly can and see lots of flowers every day.
4. Duck couldn’t fast then.
5. Before, Duck ate and Butterfly ate .

1. small; yellow 2. long; fat 3. fly 4. swim 5. fish; leaves