*Question*
Answer the following question given this paragraph: Q: Engaging in relatively simple behaviors helps maintain a nearly constant body temperature for organisms classified as what? Choices: - photophores - placoderms - endotherms - ectotherms A:
**Answer**
ectotherms

*Question*
Answer the following question given this paragraph: Natural gas burns cleaner than other fossil fuels. As a result, it causes less air pollution. It also produces less carbon dioxide than the other fossil fuels. Because it burns cleaner than other fossil fuels, natural gas has a good reputation. Still, natural gas does emit pollutants. Q: Natural gas burns cleaner and produces less carbon dioxide than fuels of what type? Choices: - renewable fuels - solar energy - biofuels - fossil fuels A:
**Answer**
fossil fuels

*Question*
Answer the following question given this paragraph: Static friction acts on objects when they are resting on a surface. For example, if you are hiking in the woods, there is static friction between your shoes and the trail each time you put down your foot (see Figure below ). Without this static friction, your feet would slip out from under you, making it difficult to walk. In fact, that's exactly what happens if you try to walk on ice. That's because ice is very slippery and offers very little friction. Q: Static friction acts on objects when they are resting on what? Choices: - a single point - their laurels - a pool of water - a surface A:
**Answer**
a surface

*Question*
Answer the following question given this paragraph: In a hydrogen replacement reaction, the hydrogen in the acid is replaced by an active metal. Q: In a hydrogen replacement reaction, the hydrogen in the acid is replaced by what? Choices: - gas - water - oxygen - an active metal A:
**Answer**
an active metal