Proofread the following text carefully and correct the five spelling errors. Within a small chamber, an internel combustion engi
ne combines a precisely measured mix of fuel (typically petrol or diesil) and air. Once ignited, this explosive combinasion causes an expansion of hot, presurised gases to exit the chamber, typically via pistons or a turbine. The chemical energy is converted, although often not very eficiently, into mechanical energy which can then be used to power motors and drive machines.
Internel should be internal, diesil should be diesel, combinasion should be combination, presurised should be pressurized, eficiently should be efficiently.
The correct answer among the choices provided is the fourth option. Personal testimony was used by the speaker to prove his point. The speaker talked about his experiences on how Britain tried to stop the war in Europe. He is credible since he was a Cabinet member during that time.
