You will be given a definition of a task first, then an example. Follow the example to solve a new instance of the task.
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.

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
Solution: Researchers did experiments on kids in order to find out _ .
Why? 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: Article: Charlie,a master carpenter ,was very well respected in his community.Everyone knew that if they wanted the best,they would call on him.Of course that meant that Charlie would never be rich.His fellow carpenters always told him that if you used inferior materials and cheap labor then you could make a lot of money.Charlie would not hear of it. One day,John,the richest man in town came to Charlie.He said that he had just bought the best piece of land in town. It overlooked the entire city.He was going to Europe for 4 months and wanted Charlie to build him the best house in town." _ ." Charlie thought about this and decided finally he would make some money.He did not get his usual great carpenters and fine materials from his normal suppliers.He built the house and covered up the flaws .After 4 months he had spent about 50%of what he usually spends on a house. John came back from Europe and immediately called Charlie and asked him to meet him at the house.When they met,John asked him if he had used the finest materials and spared no expense.Charlie said ly.John said that he was glad.He paid Charlie,then told him that he knew he was not rich and had always struggled.So he wanted to reward Charlie for all of his years of service to the community by giving Charlie this house. There are many times in our lives where we let down a little bit. When you do,you never know what is going to happen.
Answer: regretful
Solution:
When Charlie heard that he would be given the house he must have felt _