生态学可以分为两大分支：即个体生态学和群体生态学；根据研究对象的 层次，后者又可分为：种群生态学；群落生态学；生态系统生态学。
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在影响种群个体数目的因素中，主要是出生率和死亡率和年龄结构两大类。
A. 对
B. 错
Mary never does any reading in the evening, _________.
A. So does John
B. Neither does John
C. So John does
D. So did John
------He used to go out for a walk after supper.------_______________.
A. So do I
B. So did I
C. Neither did I
D. So I do
------She has a nice watch.------_________________.
A. So has she
B. So she has
C. So does Jack
D. So he does
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