燃气发动机是所有热机中最完美的，因为它结合了蒸汽机和内燃机的优点。
On television， all subject matter must be presented as entertainment.
Don't just fight in the North or the South. Always imagine every battle in your mind, where everyone is both your enemy and your friend, and all possible events happen simultaneously. That way, nothing will take you by surprise, and everything that happens will be something you've already imagined.
Mathematics is not about numbers, equations, computations, or algorithms: it is about understanding.