Choose the correct answer:
1. Statement 1 - Gases released by burning coal and petroleum are harmful.
Statement 2 - Oxides of nitrogen, sulphur, and carbon are poisonous at higher concentrations.
Statement 2 - Oxides of nitrogen, sulphur, and carbon are poisonous at higher concentrations.
2. Statement 1 - Hydropower plants convert the kinetic energy of flowing water into electricity.
Statement 1 - Hydroelectric power pollutes the environment and generate waste.
Statement 1 - Hydroelectric power pollutes the environment and generate waste.