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.

Let me give you an 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
The answer to this example can be: Researchers did experiments on kids in order to find out _ .
Here is why: It is clearly mentioned in the article that to the check effect of mood on children is the main purpose of the experiment.

OK. solve this:
Article: More than half of Americans do not take all their vacation days,even though they think they need one more holiday. And nearly a third of workers who take a break check their emails from the boss every other day and some even keep in touch hourly. "We're workaholics ',"said Samuel Nahmias."From a general perspective,this has a lot to do with the economic situation in the US. More and more people are unemployed." With jobless numbers reaching 9.6 percent,people who have jobs seem to be unwilling to take time off." _ People are not going on vacation as much and those who are going on vacation are being more selective about where they are going."Nahmias explained. Unlike European countries where four or more weeks of holiday each year is normal,27 percent of people questioned in the poll said they had 6 to 10 days of annual leave and 20 percent had less than 3 days.With more people on unemployment lists in America,those still with jobs are facing more responsibility at work,which is reflected in their lack of time off. The majority of workers who did not take time off mentioned too many responsibilities or stress at work,while some people said they simply did not have time to plan a holiday."People are more conscious of what they are doing and when they are going on vacation because they don't want to look bad in this situation,"Nahmias explained. Technology is also playing a part with smartphones enabling workers to keep in contact in ways that were not possible before.It has to do with technology and the level of concern about what is going on in the office.
Answer: they are afraid that they may lose their jobs
Answer:
Americans don't take all their vacation days because _ .