题目内容：

    A mouse was surprised and frightened to discover that the farmer and his wife had a mousetrap(老鼠夹）in the house. It ran to warn everyone, “There is a mousetrap in the house!” and wanted to get some help from them.

The hen raised its head and said, “Mr. Mouse, this mousetrap is only for you. I won’t be worried about it.” The mouse turned to the pig, “I am sorry, Mr. Mouse, but the mousetrap has nothing to do with me, either!” the pig said. Then the mouse turned to the cow. “It sounds like you have a problem, not me,” the cow said. The mouse returned to the house with head down and it was very sad because no one would help it.

That night the farmer’s wife heard a loud sound and she rushed to see what was caught. In the darkness she could not see that it was a snake. The snake bit(咬）the farmer’s wife. The wife caught a bad fever and the farmer thought the best way to treat a fever was chicken soup. So the farmer killed the hen for the soup. The wife got worse and her friends came to visit her. The farmer had to kill the pig to feed them. But the wife didn’t get better and died. Her friends came and the farmer had to kill the cow to feed all of them.

So remember when any one of us is in trouble, we may all be in trouble.

根据短文内容，回答下列问题。

1.How did the mouse feel when it discovered the mousetrap?

2.How many animals did the mouse warn in all?

3.Why was the mouse very sad?

4.What was caught by the mousetrap that night?

5.What can we learn from this story?