OG7 阅读 Q15

The third paragraph states that "the pattern is clear: as businesses generated more value from their workers, the country as a whole became richer." In this context, the word "clear" most nearly means obvious, or unmistakable.
Choices A, B, and C are incorrect because in the context of the third paragraph, the word "clear" can be seen to mean obvious, or unmistakable, not pure (choice A), keen (choice B), or untroubled (choice C).