A、One is never too old to learn. B、Look before you leap. C、A friend in need is a friend indeed. D、The early bird gets the worm.

A fox one day fell into a deep well and could find no means of escape. A thirsty goat came to the same well, and seeing the fox, inquired if the water was good. Concealing his sad situation under a merry guise, the fox sang high praise of the water, saying it was excellent beyond measure, and encouraging him to descend. The goat, mindful only of his thirst, thoughtlessly jumped down, but just as he drank, the fox informed him of the difficulty they were both in and suggested a scheme for their common escape. "If," said he, "you will place your forefeet upon the wall and bend your head, I will run up your back and escape, and will help you out afterwards." The goat readily assented and the fox leaped upon his back. Steadying himself with the goat’s horns, he safely reached the mouth of the well and made off as fast as he could. When the goat blamed him for breaking his promise, he turned around and cried out, "You foolish old fellow! If you had as many brains in your head as you have hairs in your beard, you would never have gone down before you had inspected the way up, nor have exposed yourself to dangers from which you had no means of escape."
16. How did the fox come out of the well?
17. Why did the fox sing high praise of the water?
18. What does the story try to tell us?