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: Earthquakes and volcanic eruptions usually cause the largest, most disastrous debris ( ) flows. A great many victims of the earthquake that struck Wenchuan of Sichuan province last May were killed not by the quake itself but by the sudden large amounts of debris that followed. Most debris flows occur where the soil is composed mainly of sand or colluviums ( ) . Loose soils made up of bits of sand or colluviums fall apart easily and are main material for fast -moving debris flows. Scientists have conducted endless experiments to find out how debris flows work. They have learned that the amount and the timing of water entering the soil are crucial ( ). Typically, that means debris flows often occur when a long rainy period of many weeks is followed by an intense, brief heavy rain. . More often than not, however, debris flows are started by water, in the form of rain, snow, or river flow. In 1998, heavy rains from Hurricane Mitch unleashed about one million tons of mudslides, burying thousands of people, in Central America. Water flows through the soil until it hits a hard layer of bedrock or clay. There the water builds up, filling the tiny spaces between the soil and rock. That buildup reduces the natural friction ( ) that keeps the rock and soil debris lying on the slope. If conditions are approaching dangerous levels, the slope will then fall down. Despite what scientist know about the fact, debris flows are still impossible to predict at present because there are many other uncertains affect the stability of each slope. However, one thing is known: On hillsides where one debris flow has occurred, another will eventually follow. The next debris flow could take days, weeks, or years to happen.
Answer: the possible ways to predict landslides
Solution:
The passage is mainly about _ .