Evidence from proxies indicate eight major oscillations in global temperatures over the past 800,000 years, most likely the result of
A) rising and falling sea levels that greatly impact photosynthetic activity.
B) variations in solar activity that produce different levels of radiation.
C) Milankovitch cycles of periodic variations in Earth's orbits around the sun.
D) lunar cycles in which the moon orbits at different distances from the Earth.
C
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What is a system?
a. a repeating cycle of events that occur in a predictable order b. an individual part or idea that never interacts with other individual parts or ideas c. a collection of individual items or ideas that are grouped together based solely on a single physical characteristic they have in common d. an ordered way of performing the scientific method e. a group of individual parts that interact and form a more complex whole
In urban areas, this gas from internal-combustion engines may contribute to rainfall acidity.
A. sulfur gases B. ozone C. radon D. nitrogen oxides
Which of the following is a type of body fossil?
A)trails B)bones C)burrows D)coprolites (fossil feces) E)nests
The ecosystem associated with the Aw climate is termed:
A) jungle. B) taiga. C) savanna. D) boreal.