Teacher: 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.
Teacher: Now, understand the problem? If you are still confused, see the following 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
Solution: Researchers did experiments on kids in order to find out _ .
Reason: It is clearly mentioned in the article that to the check effect of mood on children is the main purpose of the experiment.

Now, solve this instance: Article: Even people who don't understand English can enjoy Chaplin's films because they are mostly silent. It isn't what he says that makes us laugh. It depends upon actions which mean the same thing to people all over the world. He is _ of the art - a kind of world language. As a young man, he and his brother traveled to America in a small company of actors. Chaplin was then invited to join a new company that was making film comedies. Very soon he had made dozens of short films for this company. And it was in his second film that he wore the clothes which made his reputation - black hat, tight coat, baggy trousers, huge shoes, moustache and walking stick. He intended simply to make people laugh. But the odd make-up made him look both comic and sad. By the time he was thirty, Chaplin was the greatest, best known and best loved comedian in the world. He received thousands of dollars for each film he made. He had formed his own manner of acting. He was welcomed by excited crowds wherever he went. But he worked very hard and had few close friends. Perhaps that is why the sad side of the little tramp began to show more clearly in the films he made. The little man began to want more than food and a roof over his head. He began to want love. In one of his most famous films "The Gold Rush" a girl plays tricks on the little man. Then she begins to feel sorry for him and treats him kindly. He mistakes her pity for love. The girl in "City Lights" is blind. She thinks he is the most wonderful man she has ever met. But then she recovers her sight and sees what a foolish figure he is. This sadness gives Chaplin's films a depth of human experience which few comedians can equal. After living in America for forty years he moved to Switzerland. There he died on Christmas Day 1977. He once described himself as a citizen of famous pictures that were made during the 1920s and 1930s, the time of the silent films. But, to many people all over the world Chaplin will always be the king of comedy.
Answer: spent most of his time in working and had no time to make friends
Student:
Charlie Chaplin had few friends because he _ .