Answer the following question given this paragraph: The best-known method of radiometric dating is carbon-14 dating . A living thing takes in carbon-14 (along with stable carbon-12). As the carbon-14 decays, it is replaced with more carbon-14. After the organism dies, it stops taking in carbon. That includes carbon-14. The carbon-14 that is in its body continues to decay. So the organism contains less and less carbon-14 as time goes on. We can estimate the amount of carbon-14 that has decayed by measuring the amount of carbon-14 to carbon-12. We know how fast carbon-14 decays. With this information, we can tell how long ago the organism died. Q: Carbon-14 dating is a method of what kind of dating? Choices: - orbital - stratigraphy - metamorphic - radiometric A:
radiometric
Answer the following question given this paragraph: HFCs are used as a replacement for CFCs. The molecular structure of HFC134a is shown in this ball-and-stick model. Q: Hfcs are used as a replacement for what? Choices: - nitrofluorocarbons - pollutants - gases - cfcs A:
cfcs
Q: Answer the following question given this paragraph: Sponges are a source of food for many species of fish. Because sponges are anchored to a reef or rock, they can't run away from predators. However, their sharp spicules provide some defense. They also produce toxins that may poison predators that try to eat them. Q: Where are sponges most likely anchored to? Choices: - sea floor - sand - beaches - reef or rock A:
A: reef or rock
Question: Answer the following question given this paragraph: A person is able to lift the entire rear end of the automobile using only one hand with the hydraulic jack shown in the image. Hydraulic systems are similar to simple machines in that they can produce very large mechanical advantages. Q: A hydraulic jack that makes it possible to lift a car easily is an example of what, meaning it produces mechanical advantages? Choices: - quantum physics - simple weapon - complex machines - simple machine A:
Answer: simple machine
*Question*
Answer the following question given this paragraph: Science rests on evidence and logic, so it deals only with things that can be observed. An observation is anything that is detected either through human senses or with instruments and measuring devices that extend human senses. Things that cannot be observed or measured by current meanssuch as supernatural beings or eventsare outside the bounds of science. Consider these two questions about life on Earth:. Q: What term means anything that is detected either through human senses or with instruments and measuring devices that extend human senses? Choices: - variation - evaluation - evacuation - observation A:
**Answer**
observation
*Question*
Answer the following question given this paragraph: The pressure of gases in the atmosphere is greatest at sea level and decreases rapidly as altitude increases. Q: Where is the pressure of gases in the atmosphere at its greatest? Choices: - stratosphere - core - mountain ranges - sea level A:
**Answer**
sea level