A discussing two categories of factors that control population growth and assessing their relative importance B describing how growth rates in natural populations fluctuate over time and explaining why these changes occur C proposing a hypothesis concerning population sizes and suggesting ways to test it D posing a fundamental question about environmental factors in population growth and presenting some currently accepted answers

A applicable only to erratically fluctuating populations B useful, but only if its limitations are recognized C dangerously misleading in most circumstances D a complete and sufficient way to account for observed phenomena

A roughly constant population levels from year to year B regular cycles of increases and decreases in numbers C erratic increases in numbers correlated with the weather D unchecked increased in numbers over many generation

A demonstrate the difficulties ecologists face in studying density-dependent factors limiting population growth B advocate more rigorous study of density-dependent factors in population growth C prove that the death rates of any population are never entirely density-independent D underline the importance of even small density-dependent factors in regulating long-term population densities

A cite the views of other biologists B define a basic problem that the text addresses C present conceptual categories used by other biologists D describe the results of a particular study

A The reason behind changes in IQ scores. B The assessment procedures of IQ scores. C The psychological explanation for IQ scores. D The design and evolution of IQ tests.

A It has been decreasing in recent decades. B It refers to a steady decline in IQ scores. C It is about the fluctuation of the IQ scores. D It suggests a rise in IQ scores over time.

A Education. B Nutrition. C Environment. D Genetics.

A The falling of IQ scores since the mid-1970s is due to the environmental factors. B A rise in IQ scores during the 20th century can be explained by genetic changes. C Changes in IQ scores are not wholly explained by changes in general intelligence. D Different IQ tests have been made to measure different kinds of intelligence.

A They will be replaced by artificial intelligence. B They will still measure reasoning skills. C They will be difficult to be compared across time. D They will change the way we think.