I read this background article the other day: In the wiring of a building, the wires carrying the current in and out are different and never touch directly. The charge passing through the circuit always passes through an appliance (which acts as a resistor) or through another resistor, which limits the amount of current that can flow through a circuit. Appliances are designed to keep current at a relatively low level for safety purposes. The appropriate voltage and resistance in a circuit keeps the current in control and keeps the circuit safe. It is possible, however, for something to happen that causes the wire bringing the current in to come into contact with either the wire carrying the current out or the ground wire, thus causing what is called a short circuit . In a short circuit, some or all of the resistance is cut out of the circuit allowing the voltage to push a huge current through the wires.  I am facing a new situation today: Greg is an electrical engineer. He works for an engineering firm that builds houses. Yesterday, Greg was checking two of the houses. He noticed that one of the houses had short circuit. He labeled that as case A. But the other house didn't have short circuit. He labeled that as case B.  Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: In which case the incoming and outgoing current wires would touch each other, case A or case B?
Ans: case A

I read this background article the other day: In slippery conditions some riders prefer to ride fixed because they believe the transmission provides increased feedback on back tire grip. However, there is also an increased risk of loss of control in such conditions. This is especially so when taking into account the large number of riders who ride brakeless. These riders must brake entirely through the drivetrain. Ideally this is done by resisting the forward motion of the pedals, shedding speed while the bike is still moving. Alternatively, though far less efficiently, one can brake by stopping the motion of the pedals in mid-rotation, causing the rear wheel to lock in place, allowing the bicycle to skid and slow down from kinetic friction (see below).[22]  Descending any significant gradient is more difficult as the rider must spin the cranks at high speed (sometimes at 170 rpm or more), or use the brakes to slow down. Some consider that the enforced fast spin when descending increases suppleness or flexibility, which is said to improve pedalling performance on any type of bicycle; however the performance boost is negligible compared to the benefits of riding a free wheel.[23]  I am facing a new situation today: Two villages are inhabited by lots of people that ride bicycles. Hill village is located on a mountain and gets lots of rain, and Low village is situated in a valley, and has more sunny days.  Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which village has more dangerous cycling conditions?
Ans: Hill

I read this background article the other day: Unfortunately, the layer of good ozone is being destroyed by air pollution. The chief culprits are chlorine and bromine gases. They are released in aerosol sprays, coolants, and other products. Loss of ozone has created an ozone hole over Antarctica. Ozone depletion results in higher levels of UV radiation reaching Earth. In humans, this increases skin cancers and eye cataracts. It also disturbs the nitrogen cycle, kills plankton, and disrupts ocean food webs. The total loss of the ozone layer would be devastating to most life. It’s rate of loss has slowed with restrictions on pollutants, but it is still at risk.  I am facing a new situation today: Bend city used a lot of fossil fuels to generate electricity. Hop city, another city from the same county, used only alternative sources of energy.  Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which city disrupted more ocean food webs?
Ans: Bend

I read this background article the other day: Higher pressures increase the solubility of gases. You are probably familiar with this concept as it relates to carbonated beverages. Before opening the container, the inside is pressurized, so a large amount of CO 2 is dissolved in the liquid. After opening, the pressure decreases (to the ambient pressure), so the solubility of CO 2 drops, causing it to bubble out of solution. Because they are not compressible like gases, solid and liquid solutes do not have noticeable changes in solubility at different external pressures.  I am facing a new situation today: Robin is an exterminator who is making new mixtures of chemicals to use for when he gets called to kill rats in his neighborhood. To make the mixtures, he has to dissolve nitrogen gas in containers of water. In one container, container A, he dissolves the nitrogen gas under high pressure. In the other container, container B, he dissolves the nitrogen gas under low pressure.  Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which container will have lower solubility of the nitrogen gas?

Ans: container B