Two species of deer have been prevalent in the Puget Sound area of Washington State in the Pacific Northwest of the United States. The black-tailed deer, a lowland, west-side cousin of the mule deer of eastern Washington, is now the most common. The other species, the Columbian white-tailed deer, in earlier times was common in the open prairie country, it is now restricted to the low, marshy islands and flood plains along the lower Columbia River.
According to paragraph 1, which of the following is true of the white-tailed deer of Puget Sound?
A. It is native to lowlands and marshes.
B. It is more closely related to the mule deer of eastern Washington than to other types of deer.
C. It has replaced the black-tailed deer in the open prairie.
D. It no longer lives in a particular type of habitat that it once occupied.
Plant communities assemble themselves flexibly, and their structure depends on the particular history of the area. Ecologists use the term "succession" to refer to the changes that happen in plant communities and ecosystems over time. The first community in a succession is called a pioneer community, while the long-lived community at the end of succession is called a climax community. Pioneer and successional plant communities are said to change over periods from 1 to 500 years. These changes-in plant numbers and the mix of species-are cumulative. Climax communities themselves change but over periods of time greater than about 500 years.
According to paragraph 1, which of the following is NOT true of climax communities?
A. They occur at the end of a succession.
B. They last longer than any other type of community.
C. The numbers of plants in them and the mix of species do not change
D. They remain stable for at least 500 years at a time.
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