1. is "A"
2. is "A"
3. is "B"
4. is "D"
If you use the stairs at normal speed, you will survive longer, and go up higher.
When going up the stairs twice as fast, you lose energy more quickly, but height would remain the same.
Answer:
The ability to do something or act in a particular way, especially as a faculty or quality.
"The power of speech"