Answer: lessens
Step-by-step explanation:
When engines run on higher altitudes it means they are running at a lower power. Engines operate at a lower power at high altitude due to a reduction in oxygen which now makes the vehicle perform in a slow manner due to a reduction in air to power the internal combustion engine.
2) Remember to cross the rail track when it is safe and permitted by signs and signals. This is the best time to cross the rail track.