pls follow me
Explanation:
A star of one solar mass remains in main sequence for about 10 billion years, until all of the hydrogen has fused to form helium.
Answer: 0.69 m/ mile.
Explanation:
The altitude gradient between two cities X and Y = 
Given: Two cities are separated by 200 miles.
City X has an altitude of 122 meters.
City Y has an altitude of 260 meters.
The altitude gradient between two cities X and Y =

Hence, the altitude gradient between the two cites = 0.69 m/ mile.
<u>Answer</u>: an all or none response
According to the all-or-none law, it a certain threshol is crossed by a stimulus' strenght, it will cause a response in the nerve cell or muscle fiber. However, the strenght of the response will always be the same and will not vary with different stimulus strengths. The only requirement is for the threshold to be crossed.