Detailed Instructions: 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.
See one example below:
Problem: 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 _ .
Explanation: It is clearly mentioned in the article that to the check effect of mood on children is the main purpose of the experiment.

Problem: Article: While shell-like roofs, unlike anything else in the world, make the Sydney Opera House an image of timeless beauty. It is famous for being a symbol, not only of a city, but a whole country and condition too. Its creator, Danish architect Jorn Utzon , turned 85 last Wednesday. And he was awarded the Prizker Prize, known as the Nobel Prize of Architecture, on April 6. But Utzon has never seen his Opera House. The story began in 1957 when Utzon won an international competition to design an opera house in Sydney. But not everyone was enthusiastic ( ) . Utzon left his Opera project in 1966 after an argument with the local government and a storm of public criticism over the building's design. It was not completed until seven years later and Utzon has never returned to Australia to see the result of his work. "Utzon made a building well ahead of its time, and he persevered through criticism to build a building that changed the image of an entire country," said Frank Gehry, a Pritzer Architecture Prize judge. Although the Sydney Opera House was Utzon's masterpiece, it damaged his career. Upon his return to Denmark, he found work hard to come by , so he become a teacher at a university in Hawaii. Utzon said he once saw posters of the Opera House. The interiors were different from his design. But, he said, "There is no regret, for it gave me such a wonderful experience in Australia and towards which I only have love and appreciation ." Britain's Queen Elizabeth opened the Opera House in 1973, and it now holds around 3000 events every year. It is recognized as one of the great symbolic buildings of the 20th century.
Answer: in 1980
Solution:
The Sydney Opera House was completed _ .