Because in winter 1 habitat might get too cold so the bird might have to move to a warmer habitat in winter
For many common cancers, such as breast cancer, bowel cancer and prostate cancer, radiation therapy is highly effective in reducing the risk of cancer recurrence after surgery or helping the surgery be more successful.
Answer: Four conditions are needed for natural selection to occur: reproduction, heredity, variation in fitness or organisms, variation in individual characters among members of the population. If they are met, natural selection automatically results.
Explanation: