“生态学”这一学科名词最早是由德国动物学家海克尔提出的。
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行为调节、内分泌调节、遗传调节和食物调节都属于种群自动调节机制。 [ ]
A. 正确
B. 错误
生态系统中必须有的生物成分是生产者和消费者。 [ ]
A. 正确
B. 错误
The author of this passage is most probably________.
A. a historian
B. a doctor
C. a nutritionist
D. an environmentalist
The wallet which the writer found______.
A. was empty
B. had some money in it
C. had a few coins and a photograph in it
D. had an old photograph in it
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