31)
sexual reproduction is an important piece of natural selection and survival of the fittest. in order for a population to survive over time it is critical that organisms reproduce sexually to ensure
a) immigration.
b) biodiversity.
c) genetic variability.
d) survival of the fittest.

the answer to you question is   jet streams

evidence and logical support is essential for a scientist to do in order to maintain credibility. this is because no one can believe without any logic and without any evidence.hence a scientist can maintain credibility by proving himself and by answering logically so experiments prove very beneficial. logical hypothesis give conclusion which is acceptable. therefore, there are two main factors to maintain credibility by a scientist is evidence and logical support.