6. Yes, people should take quick showers to save water.
7. Yes, people should learn to recycle to reduce land pollution.
8. Yes, people should recycle plastic bottles and use glass bottles instead to minimize waste.
9. Yes, we shouldn't litter in rivers and lakes, we should help clean the environment.
10. Yes, air conditioning units should be turned off when not in use to save energy.

【Giải thích】：
6. Taking quick showers can save a substantial amount of water compared to taking a bath, conserving a precious resource.
7. Recycling reduces the amount of waste that ends up in our landfills and might otherwise contribute to land pollution.
8. Recycling and reusing of materials like plastic and glass bottles minimize waste and saves resources as new materials aren't required.
9. Dumping trash indiscriminately, particularly in water sources, leads to pollution that harms wildlife and human health and affects local ecosystems as well. Hence the need to ensure proper waste disposal and clean up initiatives to safeguard the environment
10. Powering down or switching off nonessential electronic devices including air conditioning when not in use saves energy, ultimately helping to reduce the fossil fuel usage.