阅读短文，完成下列各题。
Once there was an old farmer, with a horse which was almost as old as himself. He set out one morning with his son to sell the horse before it died. Father and son walked, because the farmer did not want the horse to be too tired.
Two men on the road said, "Why are you walking, farmer? You have a horse, It's a long way to market. "The farmer thought that it was true, so he rode on the horse, while his son walked.
Then they met two old women, "What are you doing up there, farmer? Can't you see how tired the boy is?" So the farmer got down, and his son rode instead.
Next, an old men stopped them and said, "Why are you walking, farmer? It's too hot for an old man like you to walk today," So the farmer got up behind his son, and they rode on.
Some time later, a young woman passed them, "Why aren't you walking?" she said, "It isn't far to the market. Let your poor horse have a rest." So the farmer, and his son, got down once again.
It is a fact that you cannot please all the people all the time.
简略回答问题。
小题1:Why did the father and son walk first? _________________________.
小题2:What does the story tell us? _____________________
小题3:He set out one morning with his son. (划线部分提问)
______ ______ he set out with his son?
小题4:You have a horse (否定句)
You _______ _________ a horse.
小题5:She said, "It isn't far to the market.”（改为宾语从句）
She said _______ _______ far to the market.
不能被新制的氢氧化铜氧化。写出同时符合下列条件的D的同分异构体的结构简式： 。