Answer the following question given this paragraph: Because chemical changes produce new substances, they often cannot be undone. For example, you can't change a fried egg back to a raw egg. Some chemical changes can be reversed, but only by other chemical changes. For example, to undo the tarnish on copper pennies, you can place them in vinegar. The acid in the vinegar reacts with the tarnish. This is a chemical change that makes the pennies bright and shiny again. You can try this yourself at home to see how well it works. Q: To undo the tarnish on copper pennies, you can place them in what liquid? A:
OPTIONS:
- distilled water
- honey
- seawater
- vinegar
vinegar

Answer the following question given this paragraph: Bradykinin is a peptide hormone composed of nine amino acids that lowers blood pressure. Its primary structure is arg-pro-pro-gly-phe-ser-pro-phe-arg. Would you expect bradykinin to be positively charged, negatively charged, or neutral at a pH of 6.0? Justify your answer. Q: What do we call a peptide hormone composed of nine amino acids that lowers blood pressure? A:
OPTIONS:
- angiotensin
- parcnid
- bufotenin
- bradykinin

Answer: bradykinin

Question: Answer the following question given this paragraph: In some countries, birth rates have fallen even lower than death rates. As result, their population growth rates are negative. In other words, the populations are shrinking in size. These populations have top-heavy population pyramids, like the one for Italy shown in Figure below . This is a new stage of the demographic transition, referred to as Stage 5. You might think that a negative growth rate would be a good thing. In fact, it may cause problems. For example, growth-dependent industries decline. Supporting the large aging population is also a burden for the shrinking younger population of workers. Q: What results when birth rates fall even lower than death rates? A:
OPTIONS:
- disease
- mutation
- increased growth rate
- negative growth rate
Answer: negative growth rate

input with options: Answer the following question given this paragraph: Metamorphism changes rocks by heat and pressure. These agents create an entirely new type of rock. Metamorphism changes rocks physically and/or chemically. Q: Which process changes rocks by heat and pressure? A:
OPTIONS:
- sediments
- Changes
- weathering
- metamorphism
output: metamorphism

Q: Answer the following question given this paragraph: Why is activation energy needed? A reaction won't occur unless atoms or molecules of reactants come together. This happens only if the particles are moving, and movement takes energy. Often, reactants have to overcome forces that push them apart. This takes energy as well. Still more energy is needed to start breaking bonds in reactants. The graphs in Figure below show the changes in energy in endothermic and exothermic reactions. Both reactions need the same amount of activation energy in order to begin. Q: What is required to break bonds in reactants? A:

OPTIONS:
- food
- gas
- protein
- energy

A: energy

Answer the following question given this paragraph: boundary between air masses that is stalled in one place. Q: Opportunistic diseases are usually the direct cause of death of people with what disease? A:
OPTIONS:
- heart
- parkinson
- liver
- aids
aids