In this task, you're given an article and an answer. Your task is to generate the question for the answer based on the given article.

Ex Input:
Article: What if we could replace oil with a fuel which produced no pollution and which everybody had equal access to? The good news is that we can. In fact, we are swimming in it--- literally. Hydrogen is one of the building blocks of the universe. Our own sun is basically a big, dense cloud of the stuff. And hydrogen can be used to create electricity for power, heat and light. The problem is that hydrogen is everywhere and nowhere at the same time. It does not exist as a material on its own, but is always part of something else. So it has to be separated before it can be used. Most commercial hydrogen in use now is created from natural gas. As oil will start to run out in around the year 2030, it makes sense to produce as much hydrogen as possible as soon as we can. But natural gas supplies will also begin to run out soon after. Another source is needed. Researchers are now using electricity to make water into hydrogen. Companies are working on the problem in their own areas. The first commercial hydrogen "fuel cells" for computers and mobile phones have already come on to the market. Auto companies have also invested over US $2 billion in the production of hydrogen fuelled cars. The nations of a hydrogen fuelled planet would not fight over energy recourses. There would be a great reduction in pollution. The only by-product of creating hydrogen is pure drinking water--- something that is very scarce in many parts of the world. But that is not where the good news ends. Once the costs of producing hydrogen have been brought down, it will possibly provide power for a third of the Earth's population that has no electricity. And electricity creates wealth. In South Africa over the last decade there has been a large programme of electrification. Thanks to the programme, people do not have to spend their days looking firewood to burn for heat. And with electric light, they can work long into the night. Some scientists see radical changes in the way the human race co-operates. Hydrogen creates electricity, and is also created by _ . With dual use fuel cells, everyone who consumes energy could also produce it. Late at night, a man drives home in London and connects his car into the "world-wide hydrogen web," which it supplies with electricity. A few hours later, a man in Beijing uses that electricity to power the hydrogen cell in his car. Hydrogen could be the first democratic energy source. Like all dreams of the future, it seems very far away. But the threat of war and terrorism in the Middle East has made governments and businesses more aware of the need to end oil dependency and spend more time and money on hydrogen resource. So maybe the threat of war is not a completely bad thing for the future of the human race.
Answer: It has to be separated from other materials.

Ex Output:
What is the problem with using hydrogen as energy?

Ex Input:
Article: Drinking green tea is known to be good for you. Some people suggest drinking 2-3 cups of it a day, and I would say at least one is highly advisable. As many people have already known, tea is filled with powerful antioxidants that will help stop free radicals . Free radicals are harmful to our systems in that they can lead to cell and DNA change, even cell death, and can lead to cancer. Green tea has been drunk throughout Thailand, China, India and Japan for centuries. It is known in these places that green tea can help improve digestion and mental clearness and lower one's blood sugar. It can also help control bleeding, so that injuries can be cured more quickly. Some studies even suggest that drinking green tea on a regular basis can help a person lose weight. Green tea can help a person feel fuller throughout the day with its pleasant smell and taste, and just taking the time to smell it can help ease one's hunger. In short, both studies of green tea and its history show that it is a great thing to drink for your health.
Answer: Antioxidants.

Ex Output:
Which of the following can cause DNA change and even cell death?

Ex Input:
Article: Growing up in Puerto Rico, our family was no different from so many others. My parents got married after my father came back when the war ended. Both of my parents were struggling with the hard economic realities of the time. But somehow, they found time to cherish those cultural values that shaped our everyday life. In our daily life, we celebrated together with our friends or family members every birthday, every graduation, and all holidays with music and dancing, typical foods. When we visited our family in the countryside -- a trip that took about two hours in a car, with five children fighting as to who would get a window or the front seat -- we would break into song, and somehow the trip would turn into one full of happiness and fun. We would sing not only interesting children's songs but also beautiful love songs -- songs about the love of the country though we didn't understand the meaning of the words many times. I came to Philadelphia for the first time in 1973 to do a residency in family medicine. I remember the many hours of work. I was facing issues of life and death and suffering the clearly social unfairness and issues of poverty and race. These were all aggravated by my feeling of cultural differences. An important turning point in my life happened one Saturday night when I attended a concert of Puerto Rican singer and composer Antonio Caban Vale. The music showed my familiar rhythms, and the words spoke to my heart. I had found a space to express, celebrate, and share my culture in Philadelphia. Therefore, I believe diversity is seen as an advantage and not as a disadvantage. As a Puerto Rican, I am a mixture of races and I believe in my strength because of this.
Answer: They took cultural values seriously.

Ex Output:
What do we know about the author's parents?