What determines the length of a monarch butterfly's life？
A. The time at which it matures.
B. The number of eggs it produces.
C. The environment where it lives.
D. The amount of food it eats.
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The word thrill in Paragraph 1 is closest in meaning to______.
A. opportunity
B. pleasure
C. danger
D. difficulty
According to the professor, how was Darwin's On the Origin of Species related to American
A. It called attention to social issues generated by the rise of the middle class.
B. It caused American writers to lose faith in the principles of romanticism.
C. It contributed to changes in American culture that captured the attention of writers.
D. It challenged American authors to produce works of scientific merit.
The word them in Paragraph 3 refers to______.
A. dead viruses
B. antigens
C. invading viruses
D. antibodies
How does the professor explain the lifecycle of butterflies？
A. By focusing on what they are like in the embryo stage.
By describing their development in chronological order.
C. By comparing it to the lifecycles of other insects.
D. By discussing the migration routes followed by monarchs.
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