Given a question and a context passage, generate the answer having the word or phrase from the context passage. Here, the answer should be a shortest continous span from the passage.

Context: Energy from the Sun comes from the lightest element, hydrogen, fusing together to create the second lightest element, helium. Nuclear fusion on the Sun releases tremendous amounts of solar energy. The energy travels to the Earth, mostly as visible light. The light carries the energy through the empty space between the Sun and the Earth as radiation. Solar energy has been used for power on a small scale for hundreds of years, and plants have used it for billions of years. Unlike energy from fossil fuels, which almost always come from a central power plant or refinery, solar power can be harnessed locally (Figure 1.1). A set of solar panels on a homes rooftop can be used to heat water for a swimming pool or can provide electricity to the house. Societys use of solar power on a larger scale is just starting to increase. Scientists and engineers have very active, ongoing research into new ways to harness energy from the Sun more efficiently. Because of the tremendous amount of incoming sunlight, solar power is being developed in the United States in southeastern California, Nevada, and Arizona. Solar panels supply power to the Interna- tional Space Station. Solar power plants turn sunlight into electricity using a large group of mirrors to focus sunlight on one place, called a receiver (Figure 1.2). A liquid, such as oil or water, flows through this receiver and is heated to a high temperature by the focused sunlight. The heated liquid transfers its heat to a nearby object that is at a lower temperature through a process called conduction. The energy conducted by the heated liquid is used to make electricity. This solar power plant uses mirrors to focus sunlight on the tower in the center. The sunlight heats a liquid inside the tower to a very high temperature, producing energy to make electricity. Solar energy has many benefits. It is extremely abundant, widespread, and will never run out. But there are problems with the widespread use of solar power. Sunlight must be present. Solar power is not useful in locations that are often cloudy or dark. However, storage technology is being developed. The technology needed for solar power is still expensive. An increase in interested customers will provide incentive for companies to research and develop new technologies and to figure out how to mass-produce existing technologies (Figure 1.3). Solar panels require a lot of space. Fortunately, solar panels can be placed on any rooftop to supply at least some of the power required for a home or business. This experimental car is one example of the many uses that engineers have found for solar energy. Click image to the left or use the URL below. URL: Click image to the left or use the URL below. URL: 
 Question: the source of solar power is nuclear
fusion.

Context: A personal journey into the heart of the Killing FieldsOne of the most harrowing and compelling personal documentaries of our time, ENEMIES OF THE PEOPLE exposes for the first time the truth about the Killing Fields and the Khmer Rouge who were behind Cambodias horrific genocide. More than simply an inquiry into Cambodias experience, however, ENEMIES OF THE PEOPLE is a profound meditation on the nature of good and evil, shedding light on the capacity of some people to do terrible things and for others to forgive them.Winner of a dozen top documentary festival awards, including a Special Jury Prize at Sundance and the Grand Jury Award at the Full Frame Documentary Festival, this is a riveting film that takes audiences as close to witnessing evil as they are ever likely to get. It is also a personal journey into the heart of darkness by journalist/filmmaker Thet Sambath, whose family was wiped out in the Killing Fields, but whose patience and discipline elicits unprecedented on-camera confessions from perpetrators at all levels of the Khmer Rouge hierarchy. This is investigative journalism of the highest order.In 1974, Thet Sambaths father became one of the nearly two million people who were murdered by the Khmer Rouge when he refused to give them his buffalo. Sambaths mother was forced to marry a Khmer Rouge militiaman and died in childbirth in 1976, while his eldest brother disappeared in 1977. Sambath himself escaped Cambodia at age 10 when the Khmer Rouge fell in 1979.Fast forward to 1998, and Sambath, now a journalist, got to know the children of some senior Khmer Rouge cadre and gradually earned their trust. Then, for a decade, he spent weekends visiting the home of the most senior surviving leader, Nuon Chea, aka Brother Number Two under Pol Pot. But he never used to say anything different from what he told Western journalists, says Sambath, I was low-ranking, I knew nothing, I am not a killer. Then one day he said to me Sambath, I trust you, you are the person I would like to tell my story to. Ask me what you want to know. For the next five years he told me the truth, as he saw it, including all the details of killing.Sambath also won the confidence of lower-level Khmer Rouge soldiers, now ordinary fathers and grandfathers, who demonstrated to him how they slit peoples throats. For these murderers, it was the first time they admitted what they had done. He taped their interactions and discussions about the killings, and together with British documentarian Rob Lemkin they created this landmark film.For Sambath, it has been an ongoing, lifelong personal journey to discover what was behind such horror; he neglected both his family and his own happiness in the search for truth with hope of reconciliation. ENEMIES OF THE PEOPLE is at once a cinematically beautiful, chillingly insightful, and deeply personal piece of documentary filmmaking. 
 Question: How many Cambodians died during the rule of Khmer Rouge?
nearly two million

Context: The Raiders traveled across the bay to Monster Park in San Francisco to take on the 49ers. The 49ers got on the board first with an Alex Smith to Arnaz Battle touchdown pass midway through the first quarter. The Raiders responded with a 33-yard field goal by Sebastian Janikowski. Janikowski then converted a 36 yarder early in the second quarter. Randy Moss scored his 100th career touchdown reception on a 22-yard pass from Andrew Walter, as the Raiders went into halftime with a 13-7 lead. The 49ers then went on to score 24 unanswered points in the second half, as Smith connected on touchdown passes with Battle once again, and Maurice Hicks in the third quarter. Joe Nedney converted a chip shot 19-yard field goal early in the fourth quarter. On the next Raiders play from scrimmage, Melvin Oliver recovered a fumble for a touchdown, as Walter tried to lateral a pass to LaMont Jordan, who let it hit the ground, and assumed it was an incomplete pass. Marques Tuiasosopo hit Courtney Anderson with a touchdown pass late in the game, but it was too little too late. Nedney completed the scoring with a 39-yard field goal. 
 Question: Who was ahead at halftime?

the raiders