Final answer:
Combustion can be beneficial to human activities by a. generating electricity, c. reducing waste, and conserving energy.
Step-by-step explanation:
Combustion can be beneficial to human activities in several ways. Firstly, it is a. used for generating electricity and powering vehicles, which are essential for our daily lives.
Additionally, combustion can help c. in reducing waste by burning it, minimizing the need for landfills. Lastly, combustion processes can also contribute to conserving energy by utilizing fuel sources that do not produce carbon dioxide as a by-product.