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.
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Question: Context: You're in your office when you learn there's someone with a gun wandering outside. You can hear gunshots and screams. What do you do? That's the challenge for users of a new virtual reality program called SurviVR, designed to train employees how to deal with an active shooter situation in the workplace. The program works with HTC Vive, the virtual reality headset released earlier this year. An active shooter situation is when an armed person or people actively shoot in a small, populated area with the intention to kill. There were 20 such situations in the United States last year and 20 the year before, according to FBI statistics, resulting in a total of 231 deaths. This year saw the deadliest active shooter situation in US history , with 49 people killed in a nightclub in Orlando. In the training situation, users have four choices. They can lock themselves in the office. They can hide, perhaps in the office closet. They can run for an exit. Or they can use something in the office--a computer or a cup a pair of scissors-as a weapon to fight the shooter. This is an improvement on standard active shooter training. Gallo says, which typically teachers people to lock themselves in place and hide. The "lock down" method is often ineffective, he says, and has resulted in many deaths in recent years. In the training's basic level, no one gets killed. But as the trainings become more advanced, players who make a wrong choice be shot. There's no blood; the screen simply turns black slowly. If this sounds terrifying, that's the point, says Gallo. There are plenty of training programs to teach employees how to deal with workplace violence, sometimes involving role play with toy guns. But these trainings are basically games. Gallo says, with employees relaxed and even enjoying themselves. To teach people what they really need to know for an active shooter situation, they need to be scared. "SurviVR will take the fear and turn it into confidence." Gallo says. 
 Question: What does Gallo think of the training programs involving role play with toy guns?

Answer: ineffective


Question: Context: The apolipoprotein E type 4 allele is a susceptibility gene for late-onset Alzheimer's disease. Apolipoprotein E is found in neurons, some of which contain paired helical filaments made of the microtubule-associated protein tau. Previous studies have demonstrated that the apoE3 isoform, but not the apoE4 isoform, binds tau with high avidity. Because the microtubule-associated protein MAP2c also effects microtubule assembly and stability, we examined interactions between apoE isoforms and MAP2c. Similar to the tau-binding results, apoE3, but not apoE4, bound MAP2c. Binding was detectable down to 10(-9) M MAP2c and 10(-8) M apoE3. Isoform-specific interactions of apoE with the microtubule-associated proteins MAP2c and tau might affect intracellular maintenance of microtubules and could contribute to a time-dependent pathogenesis of Alzheimer's disease. 
 Question: Which ApoE isoform is associated with atherosclerosis and Alzheimer's disease?

Answer: apoe4 isoform


Question: Context: A common misconception is that the Sun is closer to Earth in the summer and farther away from it during the winter. Instead, the seasons are caused by the 23.5o tilt of Earths axis of rotation relative to its plane of orbit around the Sun (Figure 1.1). Solstice refers to the position of the Sun when it is closest to one of the poles. At summer solstice, June 21 or 22, Earths axis points toward the Sun and so the Sun is directly overhead at its furthest north point of the year, the Tropic of Cancer (23.5o N). During the summer, areas north of the Equator experience longer days and shorter nights. In the Southern Hemi- sphere, the Sun is as far away as it will be and so it is their winter. Locations will have longer nights and shorter days. The opposite occurs on winter solstice, which begins on December 21. More about seasons can be found in the Atmospheric Processes chapter. Different parts of the Earth receive different amounts of solar radiation. Which part of the planet receives the most solar radiation? The Suns rays strike the surface most directly at the Equator. Different areas also receive different amounts of sunlight in different seasons. What causes the seasons? The seasons are caused by the direction Earths axis is pointing relative to the Sun. The Earth revolves around the Sun once each year and spins on its axis of rotation once each day. This axis of rotation is tilted 23.5o relative to its plane of orbit around the Sun. The axis of rotation is pointed toward Polaris, the North Star. As the Earth orbits the Sun, the tilt of Earths axis stays lined up with the North Star. The North Pole is tilted towards the Sun and the Suns rays strike the Northern Hemisphere more directly in summer (Figure 1.2). At the summer solstice, June 21 or 22, the Suns rays hit the Earth most directly along the Tropic of Cancer (23.5o N); that is, the angle of incidence of the Suns rays there is zero (the angle of incidence is the deviation in the angle of an incoming ray from straight on). When it is summer solstice in the Northern Hemisphere, it is winter solstice in the Southern Hemisphere. Winter solstice for the Northern Hemisphere happens on December 21 or 22. The tilt of Earths axis points away from the Sun (Figure 1.3). Light from the Sun is spread out over a larger area, so that area isnt heated as much. With fewer daylight hours in winter, there is also less time for the Sun to warm the area. When it is winter in the Northern Hemisphere, it is summer in the Southern Hemisphere. Halfway between the two solstices, the Suns rays shine most directly at the Equator, called an equinox (Figure 1.4). The daylight and nighttime hours are exactly equal on an equinox. The autumnal equinox happens on September 22 or 23 and the vernal, or spring, equinox happens March 21 or 22 in the Northern Hemisphere. Summer solstice in the Northern Hemisphere. Click image to the left or use the URL below. URL: 
 Question: the reasons for the seasons is

Answer:
the tilt of earths axis.