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: Motorists who used to listen to the radio or their favorite tunes on CDs may have a new way to entertain themselves, after engineers in Japan developed a musical road surface. A team from the Hokkaido Industrial Research Institute has built a number of"melody roads,"which use cars as tuning forks to play music as they travel. The concept works by using grooves .They are cut at very specific intervals in the road surface. The melody road uses the spaces between to create different notes. Depending on how far apart the grooves are, a car moving over them will produce a series of high or low notes, and designers are able to create a distinct tune. Paten documents for the design describe it as notches "formed in a road surface so as to play a melody without producing simple sound or rhythm and reproduce melody-like tones". There are three musical strips in central and northern Japan--one of which plays the tune of a Japanese pop song. Reports say the system was invented by Shizuo Shinoda. He scraped some markings into a road with a bulldozer before driving over them and found that they helped to produce all kinds of tones. The _ speed for melody road is 44kph,but people say it is not always easy to get the intended sound. "You need to keep the car windows closed to hear well,"wrote one Japanese blogger."Driving too fast will sound like playing fast forward, while driving around 12mph[20km/h]has a slow-motion effect, making you almost car-sick."
Answer: bulldozers
Solution:
According to the passage, melody roads use _ to create different notes.