user: Given the task definition, example input & output, solve the new input case.
In this task, you're given an article and an answer. Your task is to generate the fill-in-the-blank question for this answer based on the given article. The blanks are always at the end of the question, and can be filled with more than one word or phrase.
Example: Article: Homework can put you in a badmood , and that might actually be a good thing. Researchers from the University of Plymouth in England doubted whether mood might affect the way kids learn. To find out the answer, they did two experiments with children. The first experiment tested 30 kids. Someshapes were hidden inside a different, larger picture. The kids had to find the small shapes while sitting in a room with either cheerful or sad music playing in the background. To test their mood, the scientists asked the kids to point to one of five faces, from happy to sad. Children who listened to cheerful music tended to point to the smiley faces while the others pointed to the unhappy ones. The researchers found that sad kids took at least a second less to find the small shapes. They also found an average of three or four more shapes. In the second experiment, 61 children watched one of two scenes from a film. One scene was happy, and the other was sad. Just like in the first experiment, kids who saw the sad scene acted better compared to the others. The researchers guessed that feeling down makes people more likely to focus on a problem or difficult situation. Not all scientists agree with them, however. Other studies argued that maybe, that cheerful music in the first experiment distracted kids from finding shapes. While scientists work on finding out the answers, it still might be wise to choose when to do your tasks according to your mood. After eating a delicious ice cream, for example, write an essay. 
 Answer: whether mood affects their learning ability
Output: Researchers did experiments on kids in order to find out _ .
It is clearly mentioned in the article that to the check effect of mood on children is the main purpose of the experiment.

New input case for you: Article: A proverb says :"Time is money."But in my opinion, time is even more valuable than money. Why? Because when money is spent ,we can earn it back .However when time is gone ,it will never return .This is the reason why we must value time. There is no doubt that the time we have is unusually limited. So even an hour is extremely precious. We should make full use of our time to do useful things .As students we must not relax our efforts to engage in our studies so as to serve our society and our nation in the future. But it is pity that there are a lot of people who do not know the importance of time .They spend their valuable time smoking, drinking and so on. They do not realize that wasting time is equal to wasting a part of their valuable life. In a word, we should get into a good habit of saving time. Do not put off what can be done today until tomorrow. Laziness will not only bring us failure but also lead us to the road of poverty. 
 Answer: We must spend time in buying goods
Output:

assistant: When we say "Time is money."we mean   _