题目内容：

It was too late at night when an old man came to a small town. He found a small hotel and wanted to stay there for the night. After he went into his room, the owner said to his wife, “Look at his bag, there must be much money in it. Let's take it away when he is asleep, shall we?”

“No, no.” said the woman, “He must look for his bag tomorrow morning. If he can' t find it, he'll telephone the police. "They thought for a few minutes. Then the woman had an idea, “We have forgetful grass. Why not put some into his food? If he has the food, he will forget to take his bag away. “The old man had the food with the forgetful grass and went to bed. The next morning, when the owner got up, he found the door open, and the man had left with the bag. He was angry and woke his wife up, "What a fool! Your forgetful grass isn't useful at all.”

“No, I don't think so He must forget something.” she said. “Oh! I remember now!”cried out the man suddenly, “He forgot to pay for the night.”

Fill in the blanks according to the passage. Only one word for each blank.

From the story we know the owner of the hotel wanted to1.the old man's bag when he slept. But his wife2.with him, and she3.up with a good idea that they put some forgetful grass into the food4.that the old man would forget his bag. The forgetful grass worked. The old man really forgot something-he didn’t 5.to pay for the night.