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.

[Q]: Context: Assume that a school bus, like the one in Figure 12.2, passes by as you stand on the sidewalk. Its obvious to you that the bus is moving. It is moving relative to you and the trees across the street. But what about to the children inside the bus? They arent moving relative to each other. If they look only at the other children sitting near them, they will not appear to be moving. They may only be able to tell that the bus is moving by looking out the window and seeing you and the trees whizzing by. This example shows that how we perceive motion depends on our frame of reference. Frame of reference refers to something that is not moving with respect to an observer that can be used to detect motion. For the children on the bus, if they use other children riding the bus as their frame of reference, they do not appear to be moving. But if they use objects outside the bus as their frame of reference, they can tell they are moving. What is your frame of reference if you are standing on the sidewalk and see the bus go by? How can you tell the bus is moving? The video at the URL below illustrates other examples of how frame of reference is related to motion. MEDIA Click image to the left or use the URL below. URL: Did you ever go to a track meet like the one pictured in Figure 12.3? Running events in track include 100-meter sprints and 2000-meter races. Races are named for their distance. Distance is the length of the route between two points. The length of the route in a race is the distance between the starting and finishing lines. In a 100-meter sprint, for example, the distance is 100 meters. The SI unit for distance is the meter (1 m = 3.28 ft). Short distances may be measured in centimeters (1 cm = 0.01 m). Long distances may be measured in kilometers (1 km = 1000 m). For example, you might measure the distance a frogs tongue moves in centimeters and the distance a cheetah moves in kilometers. Maps can often be used to measure distance. Look at the map in Figure 12.4. Find Mias house and the school. You can use the map key to directly measure the distance between these two points. The distance is 2 kilometers. Measure it yourself to see if you agree. Things dont always move in straight lines like the route from Mias house to the school. Sometimes they change direction as they move. For example, the route from Mias house to the post office changes from west to north at the school (see Figure 12.4). To find the total distance of a route that changes direction, you must add up the distances traveled in each direction. From Mias house to the school, for example, the distance is 2 kilometers. From the school to the post office, the distance is 1 kilometer. Therefore, the total distance from Mias house to the post office is 3 kilometers. You Try It! Problem: What is the distance from the post office to the park in Figure 12.4? Direction is just as important as distance in describing motion. For example, if Mia told a friend how to reach the post office from her house, she couldnt just say, "go 3 kilometers." The friend might end up at the park instead of the post office. Mia would have to be more specific. She could say, "go west for 2 kilometers and then go north for 1 kilometer." When both distance and direction are considered, motion is a vector. A vector is a quantity that includes both size and direction. A vector is represented by an arrow. The length of the arrow represents distance. The way the arrow points shows direction. The red arrows in Figure 12.4 are vectors for Mias route to the school and post office. If you want to learn more about vectors, watch the videos at these URLs: (5:27) MEDIA Click image to the left or use the URL below. URL: You Try It! Problem: Draw vectors to 
 Question: When both distance and direction are considered, motion
[A]: is a vector.


[Q]: Context: Officials in the Midwestern U. S. town of Joplin, Missouri, say the death from Sundays' big tornado reaches 116 and that search efforts continue for possible survivors trapped in rubble . Search and rescue teams are conducting their third sweep through the nearly 10 kilometer - long and one - kilometer wide area of destruction left by the tornado. They are working as quickly as possible while weather conditions remain relatively stable. More storms are forecast for the area. Joplin Fire Chief Mitch Randles said there are areas with large piles of rubble that might hold survivors. "We are still finding individuals. We did rescue seven individuals from underneath rubble yesterday and, of course, we are also finding dead folks as well." Said more folks and that is why we are doing these searches. We want to make every opportunity that we can to find everybody that is in the rubble and that has survived to this point." Randles said the current sweep involves a slower pace that previous searches and that he plans a fourth search, possibly on Wednesday, using specially trained dogs. "We are searching every structure that has been damaged or destroyed in a more in-depth manner, "he said." I have dogs and dog handlers coming from all over the country do help us in that effort." Joplin City Manager Mark Rohr said the Red Cross and other volunteer organizations are helping people who were left homeless by the tornado and that the Federal Emergency Management Agency, or FEMA, is on hand to help. "Joplin is a great city. We have suffered a great loss, "said Rohr." We will recover and we will recover strongly and we have a lot of help and a lot of volunteers to make that easier." The tornado that struck Joplin was classified by the Natioonal Weather Service as an F - 4, with winds of more than 300 kilometers per hour. It lasted only 20 minutes, but it killed more that 100 people, injured more than 400 others, and destroyed or heavily damaged some 2,000 homes, businesses, churches and a hospital. Authorities have registered more than 1,700 calls about missing people and they hope to _ most of those cases soon, as victims are identified and survivors come forth and reunite with loved ones. This was the worst tornado to strike the United States in 60 years. It was the latest in a wave of violent storms that have swept Midwestern and southern states in recent weeks, leaving more than 300 people dead an causing more than $2 billion dollars in damage. 
 Question: What kind of disaster of this article is talking about?
[A]: tornado


[Q]: Context: The RTS,S/AS01(E) malaria candidate vaccine is being developed for immunization of African infants through the Expanded Program of Immunization (EPI). This phase 2, randomized, open, controlled trial conducted in Ghana, Tanzania, and Gabon evaluated the safety and immunogenicity of RTS,S/AS01(E) when coadministered with EPI vaccines. Five hundred eleven infants were randomized to receive RTS,S/AS01(E) at 0, 1, and 2 months (in 3 doses with diphtheria, tetanus, and whole-cell pertussis conjugate [DTPw]; hepatitis B [HepB]; Haemophilus influenzae type b [Hib]; and oral polio vaccine [OPV]), RTS,S/AS01(E) at 0, 1, and 7 months (2 doses with DTPwHepB/Hib+OPV and 1 dose with measles and yellow fever), or EPI vaccines only. The occurrences of serious adverse events were balanced across groups; none were vaccine-related. One child from the control group died. Mild to moderate fever and diaper dermatitis occurred more frequently in the RTS,S/AS01(E) coadministration groups. RTS,S/AS01(E) generated high anti-circumsporozoite protein and anti-hepatitis B surface antigen antibody levels. Regarding EPI vaccine responses upon coadministration when considering both immunization schedules, despite a tendency toward lower geometric mean titers to some EPI antigens, predefined noninferiority criteria were met for all EPI antigens except for polio 3 when EPI vaccines were given with RTS,S/AS01(E) at 0, 1, and 2 months. However, when antibody levels at screening were taken into account, the rates of response to polio 3 antigens were comparable between groups. RTS,S/AS01(E) integrated in the EPI showed a favorable safety and immunogenicity evaluation. Trial registration. ClinicalTrials.gov identifier: NCT00436007 . GlaxoSmithKline study ID number: 106369 (Malaria-050). 
 Question: RTS S AS01 vaccine was developed to prevent which disease?
[A]:
malaria