Paragraph Ten Usually a combination of causes produces a result. People need to distinguish between necessary and sufficient conditions. Air is a necessary condition for the maintenance of plant life, but air alone is not sufficient to produce plant

Paragraph Ten Usually a combination of causes produces a result. People need to distinguish between necessary and sufficient conditions. Air is a necessary condition for the maintenance of plant life, but air alone is not sufficient to produce plant life. Different causes at different times may produce the same result.Many causes may l______to the same result.

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