Human Impact on the Environment — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. Coal that took millions of years to form is a nonrenewable resource.
Nonrenewable resources can run out because they form too slowly.
2. Energy made from flowing rivers is called hydroelectric power.
Hydroelectric power uses moving water to make clean electricity.
3. Plants that grow back each season are a renewable resource.
Renewable resources can replace themselves within a human lifetime.
4. Reducing how much you use is called reduce.
Reducing use is the strongest way to lower waste and pollution.
5. Using something again instead of throwing it away is to reuse.
Reusing items saves materials, energy, and money over time.
6. When ocean water becomes too warm or acidic, coral reefs die.
Coral reefs are sensitive ecosystems harmed by warming and pollution.
7. An animal at risk of disappearing forever is called endangered.
Endangered species need protection so they do not go extinct.
8. Smog over cities is mostly caused by car exhaust.
Car exhaust adds harmful gases that combine to form smog.
9. Capturing rain in a barrel for later use is rainwater harvesting.
Rainwater harvesting saves clean water and reduces home water bills.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each item to its correct answer.
Solar panels
→ Renewable energy
Renewable energy
Coal power plant
→ Nonrenewable energy
Nonrenewable energy
Recycling bin
→ Conservation action
Conservation action
Pesticide runoff
→ Water pollution
Water pollution
Sorting examples helps you tell renewable, nonrenewable, helpful, and harmful apart.