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.

[EX Q]: Context: Yosemite Sam runs for mayor of a small town, and in his campaign speech, he makes several empty promises like "There's enough fresh air and sunshine in this great country of ours for everybody - and I'll see to it that you'll get your share!" As the speech continues, we see that Bugs Bunny is drinking carrot juice beneath Sam's podium. When Sam pledges to make good on a previous promise "to rid this country of every last rabbit", Bugs decides that the best way to fight him is to run for mayor against him. Bugs soon tries to win the townspeople over with Theodore Roosevelt's famous quote "I speak softly, but I carry a big stick!", which leads Sam to declare "I speak LOUD and I carry a BIGGER stick, and I use it too!".Sam has several tricks up his sleeve, but Bugs finds a way to answer every one. When Sam steals Bugs' cigar stand, Bugs switches the "Smello" cigars he had been selling for five-cent "Atom" explosive cigars (the box includes the slogan "You Will Get A BANG Out of This"). Sam gives a cigar to a man, but after the cigar explodes, the man punches Sam in the face. Sam then sends a box full of "assorted" picnic ants to steal all of the food at Bugs' picnic, which leads Bugs to hide a stick of dynamite in a watermelon being stolen.Sam rigs up a cannon at the front door of Bugs' headquarters, then turns up at the back door greeting Bugs in a friendly manner. When he taps his foot on the floor, he suggests that someone is knocking at the front door, and Bugs leaves Sam and goes to answer it, but this plan backfires when Bugs tells Sam that it was someone for him, and she said to mention St. Louis, which leads Sam to think that a pretty girl named Emma is there. Sam runs to the front door, opens it and gets shot by his own cannon.Sam's next challenge is to ask Bugs if he can "play the pi-anna". Bugs accepts, so Sam rigs an explosive in a particular piano key, and presents the piano to Bugs with a sheet of music containing the tune "Those Endearing Young Charms". When Bugs plays the tune, he deliberately hits a sour note that avoids the explosive key. When Bugs gets the note wrong a second time, it infuriates Sam, who shows Bugs how to play the tune correctly, and falls for his own trap by playing the note that sets off the explosion.After this, Sam and Bugs engage in a short pursuit through the streets of the town, which ends when they come across a parade that celebrates the newly-elected mayor - a chestnut horse who rides in a car bearing a sign that says "Our New Mare" - a literal "dark horse" candidate. This leads Bugs to make the odd suggestion to Sam to play a game of Russian Roulette and hand a gun to Sam. Sam agrees to the game, points the gun to his head, closes his eyes, pulls the trigger and hears the click of an empty barrel. Sam then passes the gun to Bugs, who points it to his head, closes his eyes and pulls the trigger as the film irises out into black in the middle. We hear the sound of a gunshot, then the film irises in on the left hand side to reveal a ducking Bugs, who holds a smoking gun as he says "I missed". A second iris appears on the right hand side to show Sam, who appears scorched and is missing his hat as a result of being hit in the face by Bugs' wayward shot. After Sam says "I hate that rabbit!", both sides of the film iris out for good. 
 Question: Who was the "dark horse" candidate?
[EX A]: the newly-elected mayor - a chestnut horse

[EX Q]: Context: In Spring 2014, Senator Jan Veleba elected as an independent candidate in 2012, joined the Party of Civic Rights and became its chairman. 
 Question: Who led Party of Civic Rights?
[EX A]: jan veleba

[EX Q]: Context: Air quality is a measure of the pollutants in the air. More pollutants mean poorer air quality. Air quality, in turn, depends on many factors. Some natural processes add pollutants to the air. For example, forest fires and volcanoes add carbon dioxide and soot. In dry areas, the air often contains dust. However, human actions cause the most air pollution. The single biggest cause is fossil fuel burning. Poor air quality started to become a serious problem after the Industrial Revolution. The machines in factories burned coal. This released a lot of pollutants into the air. After 1900, motor vehicles became common. Cars and trucks burn gasoline, which adds greatly to air pollution. By the mid-1900s, air quality in many big cities was very bad. The worst incident came in December 1952. A temperature inversion over London, England, kept cold air and pollutants near the ground. The air became so polluted that thousands of people died in just a few days. This event was called the Big Smoke. At the same time, many U.S. cities had air pollution problems. Some of the worst were in California. Cars were becoming more popular. Oil refineries and power plants also polluted the air. Mountain ranges trapped polluted air over cities. The California sunshine caused chemical reactions among the pollutants. These reactions produced many more harmful compounds. By 1970, it was clear that something needed to be done to protect air quality. In the U.S., the Clean Air Act was passed. It limits what can be released into the air. As a result, the air in the U.S. is much cleaner now than it was 50 years ago. But air pollution has not gone away. Vehicles, factories, and power plants still release more than 150 million tons of pollutants into the air each year. There are two basic types of pollutants in air. They are known as primary pollutants and secondary pollutants. Primary pollutants enter the air directly. Some are released by natural processes, like ash from volcanoes. Most are released by human activities. They pour into the air from vehicles and smokestacks. Several of these pollutants are described below. Carbon oxides include carbon monoxide (CO) and carbon dioxide (CO2 ). Carbon oxides are released when fossil fuels burn. Nitrogen oxides include nitric oxide (NO) and nitrogen dioxide (NO2 ). Nitrogen oxides form when nitrogen and oxygen combine at high temperatures. This occurs in hot exhausts from vehicles, factories, and power plants. Sulfur oxides include sulfur dioxide (SO2 ) and sulfur trioxide (SO3 ). Sulfur oxides are produced when sulfur and oxygen combine. This happens when coal burns. Coal can contain up to 10 percent sulfur. Toxic heavy metals include mercury and lead. Mercury is used in some industrial processes. It is also found in fluorescent light bulbs. Lead was once widely used in gasoline, paint, and pipes. It is still found in some products. Volatile organic compounds (VOCs) are carbon compounds such as methane. VOCs are released in many human activities, such as raising livestock. Livestock wastes produce a lot of methane. Particulates are solid particles. These particles may be ash, dust, or even animal wastes. Many are released when fossil fuels burn (see Figure 22.1). Secondary pollutants form when primary pollutants undergo chemical reactions after they are released. Many occur as part of photochemical smog. This type of smog is seen as a brown haze in the air. Photochemical smog forms when certain pollutants react together in the presence of sunlight. You can see smog hanging in the air over San Francisco in Figure 22.2. Photochemical smog consists mainly of ozone (O3 ). The ozone in smog is the same compound as the ozone in the ozone layer,(O3 ). But ozone in smog is found near the ground. Figure 22.3 shows how it forms. When nitrogen oxides and VOCs are heated by the Sun, they lose oxygen atoms. The oxygen atoms combine with molecules of oxygen to form ozone. Smog ozone is harmful to humans and other living things. Most pollutants enter the air when fossil fuels burn. Some are released when forests burn. 
 Question: Most primary pollutants are released by
[EX A]:
human activities.