A catalyst is a chemical that increases the rate of a chemical reaction without itself being changed by the reaction. The fact that they aren't changed by participating in a reaction distinguishes catalysts from substrates, which are the reactants on which catalysts work. Enzymes catalyze biochemical reactions.
Fossil fuels and unnatural energy sources still dominate in the US, this influences many problems including global warming, climate change, and pollution. Burning fossil fuels is also a problem to human health. And unnatural resources won’t be there forever whereas, renewable sources could last a long time.
I had the same question, it's most likely B.
Answer: D
Explanation: Convection transfers heat by movement such as air and water.
