Underline the correct option in each sentence. 1. Polar bears are endangered species/pollution because of melting ice. 2. Solar panels and wind turbines produce renewable energy/global warming. 3. Big cities often have problems with rural areas / overpopulation. 4. The Earth's temperature is rising because of commuter belt / global warming. 5. Many people move to urban areas / remote work to find jobs. 6. She spends two hours work-life balance / to commute to the office every day. 7. Remote work / Pollution allows employees to work from home.