Set 6: Central Ideas (Advanced)
Explanation
PASSAGE
The following text describes a geological theory. Plate tectonics is a scientific theory that explains the large-scale movements of Earth's lithosphere. The model builds on the concept of continental drift, an idea developed during the first decades of the 20th century. The geoscientific community accepted plate-tectonic theory after seafloor spreading was validated in the late 1950s and early 1960s. The lithosphere, which is the rigid outermost shell of a planet (the crust and upper mantle), is broken into tectonic plates.
According to the text, what validation led to the acceptance of plate tectonics?
Detailed Explanation
This question asks you to identify the main point of the passage. Choice C is the best answer. The text states that the community accepted the theory 'after seafloor spreading was validated in the late 1950s and early 1960s.' This directly matches Choice C.
Choice B is incorrect because fossils are not mentioned as the validator.
Choice D is incorrect because satellites are not mentioned.
Choice A is incorrect because seismographs are not mentioned. Remember that supporting details help prove the central idea but are not the main point themselves. The author's central idea should be broad enough to encompass the entire passage while still being specific enough to be meaningful. Ask yourself what the author most wants you to understand.
Key Evidence:
• "after seafloor spreading was validated"
Why others are wrong: B (Irrelevant - not mentioned), D (Irrelevant - not mentioned), A (Irrelevant - not mentioned).
🎯 Keep Practicing!
Master all sections for your best SAT score