The wood thrush makes its nest in woodlands in the northern and eastern United States. As patches of woods become smaller, increasing numbers of wood thrush nests have eggs laid in them by the brown-headed cowbird
Cowbirds live in open fields and are nest parasites; the female cowbird flies up to an unattended nest, quickly lays an egg in it, and leaves the host parents to raise their "adopted" young. Wood thrushes are decreasing in numbers because ________.
A) climate change is reducing nest site availability
B) habitat fragmentation makes it easier for cowbird parasitism to occur
C) overharvesting in the open fields has driven the cowbirds into the woodlands
D) cowbirds are an invasive species that is rapidly increasing
E) pollution of the open fields has caused a change in cowbird behavior
B
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Saudi Arabia contains approximately ________ percent of the world's known oil supplies.
A) 40 B) 10 C) 50 D) 5 E) 20
The annual temperature range at most latitudes in the Southern Hemisphere is much smaller than that in the Northern Hemisphere. The reason for this is that:
A) rainfall and cloudiness are greater in the Southern Hemisphere. B) less area is covered by desert in the Southern Hemisphere. C) there is a greater percentage of water surface in the Southern Hemisphere. D) the earth is closest to the Sun during the Southern Hemisphere summer. E) a greater proportion of the land surface is mountainous in the Southern Hemisphere.
________ pollutant levels cause gradual deterioration of a variety of physiological functions over a span of years
A) Major B) Acute C) Chronic D) Critical
Which of the following is a stage in the life cycle of a massive star?
a. Eclipse b. Asteroid c. Corona d. Supernova