2024年12月英语六级第1套真题句子解析： Meaning was measured through a daily "purpose index", which explored the extent to which participants felt that they like what they do every day and are motivated to achieve their goals.

This compound-complex sentence is from a CET-6 listening passage reporting on psychological research. First-principle breakdown: the main clause is ‘Meaning was measured through a daily purpose index’, a passive construction describing the quantification of personal sense of meaning. The non-restrictive relative clause ‘which explored the extent to which participants felt...’ modifies ‘index’, explaining what this index did. The key structure ‘the extent to which’ acts as the object of ‘explored’ and introduces a relative clause that specifies the degree of feeling. Inside it, ‘participants felt that...’ introduces a noun clause with two parallel predicates: ‘like what they do every day’ and ‘are motivated to achieve their goals’. For test-takers, first locate the main SVO to grasp the core idea, then identify ‘which’ referring to ‘index’ (not the whole sentence), and parse ‘the extent to which’ as a degree framework. Common pitfalls: misidentifying ‘which’ as referring to the whole clause; misunderstanding ‘extent to which’ as ‘extent of which’. To transfer this skill, whenever you see a long sentence with multiple clauses, start by isolating the main clause, then track pronouns and relative adverbs. The listening context also suggests that ‘purpose index’ might be explained later, so anticipate explanatory repetition.