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 need to come up with a question about the story that requires an understanding of the relationship described in the background paragraph. The generated question should not be answerable without both the background and story. Write a question about the story that requires a relationship in the background paragraph to answer. Check whether your question requires both the background paragraph and the story to answer. If your question can be answered by only one of these, try to rewrite your question so that it requires both. Note that "flipping" a word in the question can give rise to a new question where the answer will be different from the original question. Often, "flipping" a word gives rise to flipping the direction of the relationship, for example, from "increase" to "decrease."

Background Paragraph: The first evidence of baking occurred when humans took wild grass grains, soaked them in water, and mixed everything together, mashing it into a kind of slippery and wet broth-like paste.[3] The paste was cooked by pouring it onto a flat, hot rock, resulting in a bread-like substance. Later, when humans mastered fire, the paste was roasted on hot embers, which made bread-making easier, as it could now be made any time fire was created. The world's oldest oven was discovered in Croatia in 2014 dating back 6500 years ago. The Ancient Egyptians baked bread using yeast, which they had previously been using to brew beer.[4] Bread baking began in Ancient Greece around 600 BC, leading to the invention of enclosed ovens.[4] "Ovens and worktables have been discovered in archaeological digs from Turkey (Hacilar) to Palestine (Jericho) and date back to 5600 BC."[5]. 
Story: Students learned about bread making in school, and were fascinated by the history of bread. They learned ancient bread making techniques that they experimented with later on.Group A experimented with Egyptian and Greek techniques, while group B made it the Croatian and the Turkish way.
Which group of students experimented with older bread making techniques?

Background Paragraph: Clouds on Earth are made of water vapor. Venus's clouds are a lot less pleasant. They are made of carbon dioxide, sulfur dioxide and large amounts of corrosive sulfuric acid! The atmosphere of Venus is so thick that the pressure on the surface of Venus is very high. In fact, it is 90 times greater than the pressure at Earth’s surface! The thick atmosphere causes a strong greenhouse effect. As a result, Venus is the hottest planet. Even though it is farther from the Sun, Venus is much hotter even than Mercury. Temperatures at the surface reach 465°C (860°F). That’s hot enough to melt lead!. 
Story: Two friends studied different planets for their school project. Sean studied Earth's atmosphere, while Bill studied Venus's and Mercury's.
Which friend studied about a greater pressure on the surface of the planet?

Background Paragraph: Water stratification is when water masses with different properties - salinity (halocline), oxygenation (chemocline), density (pycnocline), temperature (thermocline) - form layers that act as barriers to water mixing which could lead to anoxia or euxinia.[1] These layers are normally arranged according to density, with the least dense water masses sitting above the more dense layers.

Water stratification also creates barriers to nutrient mixing between layers. This can affect the primary production in an area by limiting photosynthetic processes. When nutrients from the benthos cannot travel up into the photic zone, phytoplankton may be limited by nutrient availability. Lower primary production also leads to lower net productivity in waters.[2]. 
Story: The marine biologists studied two areas of the Black Sea. Area A, situated at the mouth of the Danube River, which presented high levels of water stratification, because of the fresh water discharged by the river; and area B, situated 35 miles south, where the water was less stratified and more oxygenated.

Which of the two areas had less dense water?