Meaning: 'According to' means based on or in relation to something.

Wrong options:

• upgrade: The word 'upgrade' is a verb that implies improvement or enhancement, which does not fit the context of discussing earnings related to socioeconomic backgrounds.
• variation: While 'variation' is relevant to the topic, it does not grammatically fit in the sentence structure where a preposition is needed to indicate the relationship.
• so that: The phrase 'so that' is a conjunction used to express purpose, which does not fit the context of establishing a relationship between earnings and backgrounds.
• in advance: The phrase 'in advance' refers to doing something beforehand, which does not relate to the context of earnings and socioeconomic backgrounds.
• thus far: The phrase 'thus far' indicates up to this point in time, which does not fit the grammatical structure needed here.
• in addressing: The phrase 'in addressing' is a gerund phrase that does not fit as it does not indicate a relationship between earnings and backgrounds.

Correct answer: thus far

Explanation: The phrase 'thus far' indicates up to this point in time, which fits contextually as it describes the extent of understanding regarding graduates' earnings.

Meaning: 'Thus far' means until now or up to this point.

Wrong options:

• according to: This phrase indicates a relationship but does not fit the context of describing the extent of understanding.
• upgrade: The word 'upgrade' does not relate to the context of understanding and is irrelevant here.
• so that: The phrase 'so that' expresses purpose, which does not fit the context of discussing the extent of understanding.
• in advance: This phrase refers to doing something beforehand, which does not apply to the context of understanding earnings.
• in addressing: This phrase is a gerund phrase that does not fit the context of describing the extent of understanding.
• variation: While 'variation' is relevant, it does not fit the context of discussing the extent of understanding graduates' earnings.

Correct answer: in addressing

Explanation: The phrase 'in addressing' indicates the action of dealing with or tackling a question, which fits grammatically and contextually as it describes how the database helps with the question.

Meaning: 'In addressing' means in the process of dealing with or tackling something.

Wrong options:

• according to: This phrase indicates a relationship but does not fit the context of describing how the database helps with the question.
• upgrade: The word 'upgrade' does not relate to the action of addressing a question and is irrelevant here.
• thus far: This phrase indicates a time frame and does not fit the context of describing how the database helps with the question.
• to help: While 'to help' indicates purpose, it does not fit grammatically in the context of the sentence.
• variation: This word does not fit as it does not describe the action of addressing a question.
• in advance: This phrase refers to doing something beforehand, which does not apply to the context of addressing a question.

Correct answer: variation

Explanation: The word 'variation' refers to differences or changes, which fits contextually as it describes the differences in graduates' earnings.

Meaning: 'Variation' means a change or difference in condition, amount, or level.

Wrong options:

• according to: This phrase indicates a relationship but does not fit as it does not describe the concept of differences in earnings.
• upgrade: The word 'upgrade' does not relate to the context of discussing differences in earnings and is irrelevant here.
• so that: The phrase 'so that' expresses purpose, which does not fit the context of discussing differences in earnings.
• in advance: This phrase refers to doing something beforehand, which does not apply to the context of discussing earnings.
• in addressing: This phrase does not fit as it does not describe the concept of differences in earnings.
• thus far: This phrase indicates a time frame and does not fit the context of discussing differences in earnings.

Correct answer: to help

Explanation: The phrase 'to help' indicates purpose, which fits grammatically and contextually as it describes the intention behind providing better information for schools.

Meaning: 'To help' means with the intention of assisting or providing support.

Wrong options:

• according to: This phrase indicates a relationship but does not fit the context of describing the purpose of providing information.
• upgrade: The word 'upgrade' does not relate to the context of assisting schools and is irrelevant here.
• thus far: This phrase indicates a time frame and does not fit the context of describing the purpose of providing information.
• in advance: This phrase refers to doing something beforehand, which does not apply to the context of assisting schools.
• variation: This word does not fit as it does not describe the purpose of providing information for schools.
• in addressing: This phrase does not fit as it does not describe the purpose of providing information for schools.