Which question can be answered by science?

Sure, here is an example of a question that can be answered by science:

"How does photosynthesis work in plants?"

This question can be answered by science because it involves understanding the biological processes that occur within plants. Scientists can conduct experiments and observations to understand how plants convert light energy, usually from the sun, into chemical energy in the form of glucose. They can study the role of chlorophyll in this process, how carbon dioxide and water are used, and how oxygen is produced as a byproduct. This is a clear example of a question that can be answered through scientific investigation and understanding.