1.

The Correct Answer is (B) — The passage describes a new discovery of scientists, magnetic properties in atomic vibrations, making choice (B) correct. The passage does not focus on new technologies (A) or the measurement of sound waves (D). Nor does the passage focus on the comparison of magnetic and thermodynamic properties of sound, so choice (C) can also be eliminated.

2.

The Correct Answer is (D) — The author includes this paragraph right after enumerating some of his team’s results on the properties of phonons, so it can be inferred that he is here proposing a theory to explain these results, making choice (D) correct. He is not concerned in this paragraph with establishing his authority (A), suggesting new areas for research (B), or providing background (C).

3.

The Correct Answer is (C) — Choice (C) is correct because it captures the author’s enthusiasm and hopes for future research, such as in lines 76-91. Since the author spends the majority of the passage explaining the evidence about magnetic properties of sound waves, it can be inferred that he is excited about the claim, so choices (B) and (D) can be eliminated. His discussion of evidence also suggests that he does not believe the claim to be unsupported, eliminating (A).