Question: Q: What is something that all machines must overcome? Choices: - stress - work - temperature - friction A:
Answer: friction

Question: Q: Burning gas to run our cars is an example of how human activity is contributing to what global event? Choices: - ozone change - carbon change - metamorphic change - climate change A:
Answer: climate change

Question: Q: What is used in the growth, development, functioning and reproduction of all known living organisms and many viruses? Choices: - viruses - bacteria - enzymes - dna A:
Answer:
dna