What is the meaning of the word 'popular' as it is used in the third paragraph?

Correct Answer: D

Rationale: In the context provided, 'popular' refers to magazines intended for the general public. The paragraph mentions that Infotrac indexes hundreds of popular magazines and newspapers, including medical journals such as the Journal of the American Medical Association and New England Journal of Medicine. These magazines target a wide audience, making choice D ('for the general public') the correct answer. Choices A, B, and C are incorrect as they do not align with the context of the paragraph.

Correct Answer: A

Rationale: 'Elasticity' refers to the ability of the arterial walls to resist and be flexible, which affects blood pressure. In the provided extract, it is mentioned that an increase in blood pressure can occur if the arterial walls lose some of their elasticity with age or disease. This demonstrates that elasticity refers to the property of being able to resist and be flexible, supporting choice A as the correct answer. The other choices, B, C, and D, do not accurately reflect the concept of elasticity in the context of arterial walls and blood pressure.

Correct Answer: C

Rationale: In the context of the second paragraph, 'phenomenon' refers to something significant and unusual, specifically describing the scientific phenomenon known as the Doppler Effect. This effect explains the change in frequency of sound waves when a source of sound and the observer are in relative motion. Choices A, B, and D are incorrect because they do not accurately reflect the meaning of 'phenomenon' in this context. 'Lifeless to the senses,' 'nonchalant,' and 'chemical in origin' do not align with the description of the Doppler Effect, which is a notable and uncommon scientific occurrence.

Correct Answer: A

Rationale: Sound waves that are closer together have a higher pitch. This is explained by the Doppler Effect, where as a source of sound moves closer to an observer, the waves are compressed, resulting in a higher frequency and a higher pitch. Conversely, when the source moves away, the waves are stretched, leading to a lower frequency and a lower pitch. Therefore, choice A is correct. Choices B, C, and D are incorrect as they do not accurately describe the relationship between sound wave frequency and pitch.

Correct Answer: B

Rationale: Sound waves that are farther apart have a lower pitch. The Doppler Effect explains that as objects emitting sound move away, the sound waves become more spaced out, resulting in a lower frequency and a lower pitch. Choice A is incorrect because waves that are closer together have a higher frequency and a higher pitch. Choices C and D are not directly related to determining the pitch of sound waves.