Given a context passage, generate a question from the passage such that its answer is shortest continous span from the passage.
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Question: To determine the validity of the rapid antigen test (RAT) OSOM StrepA Genzyme for the diagnosis of acute pharyngitis caused by group A beta-haemolytic strep (GABHS). Diagnostic techniques survey. Urban primary care centre, Spain. All patients over 14 years old seen in 6 surgeries with sore throat and 2 or more Centor criteria: pharyngotonsillar exudate, tender laterocervical nodes, absence of coughing, and/or history or presence of fever. Pharyngeal swabs were taken from all the patients, one for RAT and another to send for culture in the microbiology department. A total of 182 patients were evaluable, with a mean age of 30.6 (12.1) years of which 116 were women (63.7%); 63 patients had 2 Centor criteria; 83 had 3 and 36, the 4 criteria. The culture was positive in 102 patients (56%), with GABHS showing infection in forty (22%; 95% confidence interval [CI], 21.2-22.8). Group C Streptococcus was isolated in 26 patients (14.3%). GABHS was higher among patients with four Centor criteria (38.9% vs 25.3% observed among those with 3 criteria and 7.9% with 2 criteria; P<.001). Sensitivity of RAT was 95%, with a specificity of 93%, a positive predictive value of 79.2% and a negative predictive value of 98.5%. These results show the usefulness of RAT for diagnosing streptococcal pharyngitis. Its use should be spread to all primary care practices.

Answer: Centor criteria are used for which disease?


Question: Freshwater below Earths surface is called groundwater. The water infiltrates, or seeps down into, the ground from the surface. How does this happen? And where does the water go? Water infiltrates the ground because soil and rock are porous. Between the grains are pores, or tiny holes. Since water can move through this rock it is permeable. Eventually, the water reaches a layer of rock that is not porous and so is impermeable. Water stops moving downward when it reaches this layer of rock. Look at the diagram in Figure 13.11. It shows two layers of porous rock. The top layer is not saturated; it is not full of water. The next layer is saturated. The water in this layer has nowhere else to go. It cannot seep any deeper into the ground because the rock below it is impermeable. The top of the saturated rock layer in Figure 13.11 is called the water table. The water table isnt like a real table. It doesnt remain firmly in one place. Instead, it rises or falls, depending on how much water seeps down from the surface. The water table is higher when there is a lot of rain and lower when the weather is dry. An underground layer of rock that is saturated with groundwater is called an aquifer. A diagram of an aquifer is shown in Figure 13.12. Aquifers are generally found in porous rock, such as sandstone. Water infiltrates the aquifer from the surface. The water that enters the aquifer is called recharge. Most land areas have aquifers beneath them. Many aquifers are used by people for freshwater. The closer to the surface an aquifer is, the easier it is to get the water. However, an aquifer close to the surface is also more likely to become polluted. Pollutants can seep down through porous rock in recharge water. An aquifer that is used by people may not be recharged as quickly as its water is removed. The water table may lower and the aquifer may even run dry. If this happens, the ground above the aquifer may sink. This is likely to damage any homes or other structures built above the aquifer. One of the biggest aquifers in the world is the Ogallala aquifer. As you can see from Figure 13.13, this aquifer lies beneath parts of eight U.S. states. It covers a total area of 451,000 square kilometers (174,000 square miles). In some places, it is less than a meter deep. In other places, it is hundreds of meters deep. The Ogallala aquifer is an important source of freshwater in the American Midwest. This is a major farming area, and much of the water is used to irrigate crops. The water in this aquifer is being used up ten times faster than it is recharged. If this continues, what might happen to the Ogallala aquifer? The top of an aquifer may be high enough in some places to meet the surface of the ground. This often happens on a slope. The water flows out of the ground and creates a spring. A spring may be just a tiny trickle, or it may be a big gush of water. One of the largest springs in the world is Big Spring in Missouri, seen in Figure 13.14. Water flowing out of the ground at a spring may flow downhill and enter a stream. Thats what happens to the water that flows out of Big Spring in Missouri. If the water from a spring cant flow downhill, it may spread out to form a pond or lake instead. Lake George in New York State, which is pictured in Figure 13.15, is a spring-fed lake. The lake basin was carved by a glacier. Some springs have water that contains minerals. Groundwater dissolves minerals out of the rock as it seeps through the pores. The water in some springs is hot because it is heated by hot magma. Many hot springs are also mineral springs. Thats because hot water can dissolve more minerals than cold water. Grand Prismatic Spring, shown in Figure 13.16, is a hot mineral spring. Dissolved minerals give its water a bright blue color. The edge of the spring is

Answer: top of an underground rock layer that is saturated with water


Question: 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.

Answer:
What does Gallo think of the training programs involving role play with toy guns?