Because experiments involve careful manipulation of all factors of interest and careful control of all others, which experiment would not be ethically allowable? the effect of classical music on the ability to solve crossword puzzles the effect of room lighting on color preference the effect of supplementary vitamins on retirement age the effect of prolonged solitary confinement of toddlers on language development

Based on the  choices, I believe the experiment that would not be ethically allowed is the effect of prolonged solitary confinement of toddlers on language development. This is because this might negatively affect the language and also mental growth of the toddlers. Toddlers are very fragile and sensitive hence any confinement will affect their growth. It is also against their rights.

Humans can affect weathering and erosion in several ways.  humans cause  increases in acid rain and pollution, which increase the amount of  weathering  agents in the air and water, and then on land.for an easy answer: 1) acid rain2) pollution

Essential for a scientist to do for credibility

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.