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The amount of uranium within nuclear fuel rods is enough to sustain a chain reaction but is less than the critical mass necessary for the reaction to become explosive.
Answer: science
Explanation: she was a scientist
Answer:
1 migration
2 the northern regions have become warm
Secondary consumer
(In detail) A secondary consumer eats the primary consumers while the primary eats the producers. Primary consumers are herbivores while secondary consumers can be omnivores and carnivores.