sat suite question viewer
Scientists were able to isolate a relatively pure sample of selenium in 1817, the same year they first discovered the element’s existence. blank the isolation process took longer for molybdenum, which was isolated in its pure form three years after scientists first discovered it.
Which choice completes the text with the most logical transition?
Explanation
Choice A is the best answer. "By contrast" logically signals that the information in this sentence—that isolating molybdenum was a relatively long process—contrasts with the previous information that isolating selenium was a short process.
Choice B is incorrect because "thus" illogically signals that the information in this sentence is a result of the previous information about selenium’s short isolation process. Instead, the sentence presents contrasting information about molybdenum’s longer isolation process. Choice C is incorrect because "similarly" illogically signals that the information in this sentence is similar to the previous information about selenium’s short isolation process. Instead, the sentence presents contrasting information about molybdenum’s longer isolation process. Choice D is incorrect because "for instance" illogically signals that the information in this sentence exemplifies the previous information about selenium’s short isolation process. Instead, the sentence presents contrasting information about molybdenum’s longer isolation process.