You are given a background paragraph that describes one or more causal or qualitative relationships such as a relationship in economics or a scientific law and a story that makes use of the concepts or the relationship described in the provided paragraph. You are also given a question about the story that requires an understanding of the relationship described in the background paragraph and the story. You need to come up with an answer to the given question; the answer will be a span from either the question or the story. In order to correctly answer the given question, you need to understand the relationship mentioned in the background paragraph and should be able to use it to understand that in the story. Your answer can not consist of any word that is not mentioned in any of these: the background paragraph, the story, or the question. You can directly copy and paste a span from the story or the question while answering the given question.

Background Paragraph: Gasoline-powered vehicles emit a lot of harmful materials. Nitrogen oxides are formed when atmospheric nitrogen reacts with oxygen at the high temperatures found in a car engine. Carbon monoxide is a by-product of incomplete combustion of hydrocarbons. Evaporated and unused fuel releases volatile hydrocarbons into the atmosphere to help form smog. The presence of a catalytic converter in the exhaust system of the car causes these materials to react and be changed into less harmful products.
Story: After decades of debate, Brunei decided to adopt electrical vehicles and use them extensively, ultimately phasing out gasoline powered vehicles. Their neighbor Nepal decided to continue using gasoline-powered vehicles extensively.
Question: Which country contributed to the formation of more nitrogen oxides?
Nepal.

Background Paragraph: Rain dissolves fertilizer in the soil. Runoff carries it away. The fertilizer ends up in bodies of water, from ponds to oceans. Nitrogen is a fertilizer in the water. Since there is a lot of nitrogen, it causes algae to grow out of control. Pictured below is a pond covered with algae ( Figure below ). Algae use up carbon dioxide in the water. After the algae die, decomposers break down the dead tissue. The decomposers use up all the oxygen in the water. This creates a dead zone. A dead zone is an area in a body of water where nothing grows because there is too little oxygen. There is a large dead zone in the Gulf of Mexico ( Figure below ). The U.S. states outlined on the map have rivers that drain into the Gulf of Mexico. The rivers drain vast agricultural lands. The water carries fertilizer from these areas into the Gulf.
Story: Park farm and Fiddle farm provided Red city with tonnes of produce annually. Fiddle farm used and abundance of fertilizers and pesticides, while Park farm didn't use any of those substances.
Question: Which farm caused more fertilizer to end up in oceans?
Fiddle.

Background Paragraph: Liquid water is a fluid. The hydrogen bonds in liquid water constantly break and reform as the water molecules tumble past one another. As water cools, its molecular motion slows and the molecules move gradually closer to one another. The density of any liquid increases as its temperature decreases. For most liquids, this continues as the liquid freezes and the solid state is denser than the liquid state. However, water behaves differently. It actually reaches its highest density at about 4C.
Story: Mark decides he want a cold drink and puts a bottle of warm water in his freezer. By doing this he makes the water colder and as water cools its density increases eventually freezing and becoming a solid, Ice. After a while mark forgets that he put the bottle of water in the freezer. He eventually remembers and comes back to check and the bottle of water is frozen solid. Because of this he leaves the bottle out on his kitchen counter for a few hours and returns to a nice cold bottle of water.
Question: Will lowering the temperature of water cause it's density to increase or decrease?
increase.