Problem: I read this background article the other day: As shown here, pressure decreases to less than 25% of ground-level atmospheric pressure when we get to an altitude of about six miles. Since this is a common cruising altitude for commercial airplanes, pressurized cabins are needed for the comfort and survival of the passengers. This is because the density of the air decreases along with the decreasing air pressure, so there is less oxygen in a breath of air. You've probably noticed this effect in high-mountain areas, as it often feels harder to breath. I am facing a new situation today: Marco is sitting at the bottom of a mountain and painting a picture of it. Lauren, Marco's friend, is sitting about halfway up the mountain and painting a picture of the horizon. The two will compare paintings after they complete their drawings and then will switch places and repeat the task. These two friends do this a couple times a year, and they always enjoy seeing how the other person paints the same object. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Is the air pressure higher or lower where Marco is sitting?

A: higher

Problem: I read this background article the other day: Air pollution is harmful to human beings and other living things. About 22 million people die from air pollution each year. Breathing polluted air increases the risk of developing lung diseases such as asthma and lung cancer. Breathing bad air also increases the chances of dying from other diseases. Children are most likely to be affected by air pollution. That's because their lungs are still developing and growing. Children also take in more air for their size than adults do. Some air pollutants damage the environment as well as the health of living things. The type of damage depends on the pollutant. Air pollution can also harm the environment. I am facing a new situation today: Tree city and Leaf city were the two biggest cities in Boulderland. Tree city burned lots of gas and other fossil fuels, while Leaf city was very protective towards its environment. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which city caused more harm to human beings?

A: Tree

Problem: I read this background article the other day: Sugaring is a food preservation method similar to pickling. Sugaring is the process of desiccating a food by first dehydrating it, then packing it with pure sugar. This sugar can be crystalline in the form of table or raw sugar, or it can be a high sugar density liquid such as honey, syrup or molasses. The purpose of sugaring is to create an environment hostile to microbial life and prevent food spoilage. Sugaring is commonly used to preserve fruits as well as vegetables such as ginger. From time to time sugaring has also been used for non-food preservations. For example, honey was used as part of the mummification process in some ancient Egyptian rites. A risk in sugaring is that sugar itself attracts moisture. Once a sufficient moisture level is reached, native yeast in the environment will come out of dormancy and begin to ferment the sugars into alcohol and carbon dioxide. This leads to the process of fermentation. Although fermentation can be used as a food preservation method, it must be intentionally controlled, or the results will tend to be unpleasant. I am facing a new situation today: Ann decided to candy half of the fruit he received as a gift. She kept the other half to eat fresh and do juicing. She candied ginger, plums pears, and she didn't candy apples, oranges apricots and bananas. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which fruit contains more crystallized sugar, pears or oranges?

A: pears

Problem: I read this background article the other day: The quantity of small plastic fragments floating in the north-east Pacific Ocean increased a hundredfold between 1972 and 2012.Marine pollution is a generic term for the harmful entry into the ocean of chemicals or particles. The main culprits are those using the rivers for disposing of their waste. The rivers then empty into the ocean, often also bringing chemicals used as fertilizers in agriculture. The excess of oxygen-depleting chemicals in the water leads to hypoxia and the creation of a dead zone.Marine debris, also known as marine litter, is human-created waste that has ended up floating in a lake, sea, ocean, or waterway. Oceanic debris tends to accumulate at the center of gyres and coastlines, frequently washing aground where it is known as beach litter.In addition, the Pacific Ocean has served as the crash site of satellites, including Mars 96, Fobos-Grunt, and Upper Atmosphere Research Satellite. I am facing a new situation today: The Marlan Sea and The Jowal Sea are two bodies of water currently being studied by scientists at the Hamford Research Complex. The goal of the study is to find out which sea would be a better choice to support the construction of an experimental underwater laboratory. The employees first begin by analyzing the surrounding regions of the two seas. They discover that the Marlan Sea has many rivers flowing into it. The vast majority of these rivers are located near farms that grow crops to sell to the local cities. The Jowal Sea is surrounded by mostly uninhabited land. The rivers that flow into it have almost no human civilizations near them and instead are surrounded by flat plains and some forests. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which sea has less oxygen in it?

A:
Marlan