Complete this question with the most appropriate of the options lettered A – E Her promotion letter was found in a file after a _________search.

Analyze the question

The sentence is: "Her promotion letter was found in a file after a _____ search." We need an adjective that describes the kind of search that finally turned up the letter.

Explain the concept

This is a test of vocabulary and collocation, meaning which words naturally go together. A "search" is usually described as thorough, careful, diligent, painstaking or extensive.

Go through the options

• A. composite: means made up of several parts, as in "composite material". It does not describe a search.
• B. concrete: means solid or real, as in "concrete evidence". It is not used for a search.
• C. diligent: means careful and persistent. "A diligent search" is a standard phrase, so it fits well.
• D. fluent: describes smooth speech or language skill, so it does not fit.
• E. through: this looks like "thorough", but "through" is a preposition or adverb and cannot modify "search". The correct adjective is spelled thorough. It is a spelling trap.

Note on the key

Option E is a misspelling of "thorough", so it is not a valid word for this blank.

Answer: C. diligent

Tip: In "fill in the blank" questions, ask yourself, "Which word do I usually hear before this noun?" Also watch for look-alike words such as through/thorough and quiet/quite, because examiners like to use them as traps.