instruction:
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.
question:
Context: Do you know what your blood type is? Maybe you have heard people say that they have type A or type O blood. Blood type is a way to describe the type of antigens, or proteins, on the surface of red blood cells (RBCs). There are four blood types; A, B, AB, and O. 1. Type A blood has type A antigens on the RBCs in the blood. 2. Type AB blood has A and B antigens on the RBCs. 3. Type B has B antigens on the RBCs. 4. Type O does not have either A or B antigens. The ABO blood group system is important if a person needs a blood transfusion. A blood transfusion is the process of putting blood or blood products from one person into the circulatory system of another person. The blood type of the recipient needs to be carefully matched to the blood type of the donor. Thats because different blood types have different types of antibodies, or proteins, released by the blood cells. Antibodies attack strange substances in the body. This is a normal part of your immune response, which is your defense against disease. For example, imagine a person with type O blood was given type A blood. First, what type of antibodies do people with type O blood produce? They produce anti-A and anti-B antibodies. This means, if a person with type O blood received type A blood, the anti-A antibodies in the persons blood would attack the A antigens on the RBCs in the donor blood ( Figure 1.1). The antibodies would cause the RBCs to clump together, and the clumps could block a blood vessel. This clumping of blood cells could cause death. A person with type O blood has A and B antibodies in his/her plasma; if the person was to get type A blood instead of type O, his/her A antibodies would attach to the antigens on the RBCs and cause them to clump together. People with type A blood produce anti-B antibodies, and people with type B blood produce anti-A antibodies. People with type AB blood do not produce either antibody. The second most important blood group system in human blood is the Rhesus (Rh) factor. A person either has, or does not have, the Rh antigen on the surface of their RBCs. If they do have it, then the person is positive. If the person does not have the antigen, they are considered negative. Recall that people with type O blood do not have any antigens on their RBCs. As a result, type O blood can be given to people with blood types A, B, or AB. If there are no antigens on the RBCs, there cannot be an antibody reaction in the blood. People with type O blood are often called universal donors. The blood plasma of AB blood does not contain any anti-A or anti-B antibodies. People with type AB blood can receive any ABO blood type. People with type AB blood are called universal recipients because they can receive any blood type. The antigens and antibodies that define blood type are listed as follows ( Table 1.1). Blood Type Antigen Type Plasma Antibodies A B AB O A B A and B none anti-B anti-A none anti-A, anti-B Can Receive Blood from Types A,O B,O AB, A, B, O O Can Donate Blood to Types A, AB B, AB AB AB, A, B, O 
 Question: a person with blood type a can receive blood from
answer:
a and o.


question:
Context: Comet ISON, formally known as C/2012 S1, was a sungrazing comet discovered on 21 September 2012 by Vitali Nevski ( , Vitebsk, Belarus) and Artyom Novichonok ( , Kondopoga, Russia). 
 Question: By whom was Comet ISON discovered?
answer:
artyom novichonok


question:
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: What year does Thet Sambath seek confessions and explanations?
answer:

1998


