There was a frog. He lived in a well(井). He had never left the well. He thought the sky was as big as the well.
One day, a bird flew to the well. The frog asked the bird, "Where do you come from?"
The bird said, "I come from the sky. I flew a long way and became thirsty, so I came down to get some water to drink."
The frog said, "Friend, don't lie(欺骗)to me! The sky is only as big as the mouth of the well. Why did you fly so far?"
The bird laughed and said, "You are wrong. The sky is big and endless(无边无际的)!"
The frog smiled and said, "My friend, I sit in the well every day. When I look up, I can see the sky. I can't make a mistake(错误)."
The bird also smiled and said, "My friend, if you don't believe me, jump out of the well and have a look."
The frog jumped out of the well. He was very surprised. He found that the bird was right. The sky was really big.
a. A bird flew to the well.
b. The frog jumped out of the well.
c. The frog lived in a well.
d. The frog talked with the bird.