请先阅读下面短文，掌握其大意，然后从各小题所给的A 、B、C、D四个选项中选出可以填入相应空白处的最佳选项。

    Things like Hula hoops（呼啦圈）used to be very popular. Did you ever own any of these? If you didn't, don't feel too bad. They were all fads. A fad is something that becomes very 1 among a large number of people, but only for a short time.2 can become a fad very quickly, but can stop being popular just as quickly.3 it is no longer “cool,” a fad goes away. Anything can become a(n)4-fashion, food, music, technology, even language.

In the late 1970s, Erno Rubik, a professor was looking for a 5 way to teach his students about 3D objects. He 6 a six-color plastic object that would be called the Rubik's Cube(魔方). The goal was to get each side of the cube a7color. It was very challenging. It took a few years for the toy to become popular, but then8, in 1982, it seemed everyone had one. People bought over a hundred million of the9. There were 50 books available that year offering solutions(解决办法). Then, just as suddenly as the craze (风尚) started, it10. By 1983, people were not interested in the Rubik's Cube anymore, perhaps because so many people 11 had one in their home.

    In 2012, a South Korean musician named Psy released a song called “ Gangnam (江南) Style.” The music video shows Psy pretending (假装) to horse-ride while he is dancing. In six months, it became the first Youtube (一视频网站) video ever to reach a billion views (观看). Six months after that,12 went on to reach two billion views. The song and video started a worldwide 13 craze. “Gangnam Style” had a huge influence on world popular culture. U.S. President Barack Obama and U.K. Prime Minister David Cameron even 14 the dance. “Gangnam Style” became less and less popular,15 the “Korean Wave” of culture remains popular all over the world.