I read this background article the other day: The lungs of mammals are unique in having alveoli . These are tiny, sac-like structures. Each alveolus is surrounded by a network of very small blood vessels (see Figure below ). Because there are millions of alveoli in each lung, they greatly increase the surface area for gas exchange between the lungs and bloodstream. Human lungs, for example, contain about 300 million alveoli. They give the lungs a total surface area for gas exchange of up to 90 square meters (968 square feet). That's about as much surface area as one side of a volleyball court! I am facing a new situation today: David is investigating the breathing process of different organisms. He found that humans have alveoli to help them with gas exchange. He got curious about other organisms that do not have alveoli. To compare these two groups he labeled organisms with alveoli as group A and organisms without alveoli as group B. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which group would have network of small blood vessels in the lungs, group A or group B?
Ans: group A

I read this background article the other day: Fish reproduce sexually. They lay eggs that can be fertilized either inside or outside of the body. In most fish, the eggs develop outside of the mother's body. In the majority of these species, fertilization also takes place outside the mother's body. The male and female fish release their gametes into the surrounding water, where fertilization occurs. Female fish release very high numbers of eggs to increase the chances of fertilization. I am facing a new situation today: Two neighboring ponds were stocked with adult fish last year. Hill pond had a very nice winter and the fish started reproducing normally, while Mound pond had no fish reproducing this spring. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which pond had fewer fish release their gametes into the surrounding water?
Ans: Mound

I read this background article the other day: Cavitation is, in many cases, an undesirable occurrence. In devices such as propellers and pumps, cavitation causes a great deal of noise, damage to components, vibrations, and a loss of efficiency. Cavitation has also become a concern in the renewable energy sector as it may occur on the blade surface of tidal stream turbines.When the cavitation bubbles collapse, they force energetic liquid into very small volumes, thereby creating spots of high temperature and emitting shock waves, the latter of which are a source of noise. The noise created by cavitation is a particular problem for military submarines, as it increases the chances of being detected by passive sonar. I am facing a new situation today: Stephanie and Barb are two friends that belong to a sailing club. They are having a lunch at the cafe in the club and discussing their latest boat purchases. Stephanie mentions that her latest boat she has been using has cavitation. Barb takes a bite of her sandwich and remarks that the boat she is currently using doesn't have any cavitation. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Will Stephanie's boat require more or less fuel than Barb's to travel the same distance?
Ans: more

I read this background article the other day: Quicksand forms in saturated loose sand when the sand is suddenly agitated. When water in the sand cannot escape, it creates a liquefied soil that loses strength and cannot support weight. Quicksand can form in standing water or in upwards flowing water (as from an artesian spring). In the case of upwards flowing water, forces oppose the force of gravity and suspend the soil particles. The saturated sediment may appear quite solid until a sudden change in pressure or shock initiates liquefaction. This causes the sand to form a suspension and lose strength. The cushioning of water gives quicksand, and other liquefied sediments, a spongy, fluid-like texture. Objects in liquefied sand sink to the level at which the weight of the object is equal to the weight of the displaced soil/water mix and the submerged object floats due to its buoyancy. I am facing a new situation today: Rob is competing in a cross country race. After running about a mile he reached a place with two signs, sign A and sign B. Sign A says that it's a quicksand. But sign B says that it's not a quicksand. He has to decide which way to go. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Would sing B indicate spongy texture or not spongy texture of the soil?
Ans: not spongy texture