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.
One 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 is here: 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.

Now, solve this: Article: Taste is such a subjective matter that we don't usually conduct preference tests for food. The most you can say about anyone's preference is that it's one person's opinion. But because the two big cola companies--Coca-Cola and Pepsi Cola are marketed so aggressively, we've wondered how big a role taste preference actually plays in brand loyalty. We set up a taste test that challenged people who identified themselves as either Coca-Cola or Pepsi fans: Find your brand in a blind tasting. We invited staff volunteers who had a strong liking for either Coca-Cola Classic or Pepsi, Diet Coke, or Diet Pepsi. These were people who thought they'd have no trouble telling their brand from the other brand. We eventually located 19 regular cola drinkers and 27 diet cola drinkers. Then we fed them four unidentified samples of cola one at a time, regular colas for the one group, diet versions for the other. We asked them to tell us whether each sample was Coke or Pepsi; then we analyzed the records statistically to compare the participants' choices with what mere guess-work could have accomplished. Getting all four samples right was a tough test, but not too tough, we thought, for people who believed they could recognize their brand. In the end, only 7 out of 19 regular cola drinkers correctly identified their brand of choice in all four trials. The diet-cola drinkers did a little worse----only 7 of 27 identified all four samples correctly. While both groups did better than chance would predict, nearly half the participants in each group made the wrong choice two or more times. Two people got all four samples wrong. Overall, half the participants did about as well on the last round of tasting as on the first, so tiredness, or taste _ , was not a factor. Our preference test results suggest that only a few Pepsi participants and Coke fans may really be able to tell their favorite brand by taste and price.
Answer: reveal which cola is more to the liking of the drinkers
Solution:
According to the passage the preference test was conducted in order to _ .