IMO Practice Test — Reading Comprehension Grammar

In 'The findings, though preliminary, were promising', the word 'preliminary' most nearly means:

'The reform empowered citizens but alienated officials.' What can be inferred?

In 'Chair the meeting promptly', 'Chair' functions as a:

'The author dismisses the theory as untenable.' The tone toward the theory is:

'The scheme, whose flaws were obvious, was still approved.' What does 'whose' refer to?

In 'a watershed moment', 'watershed' here means:

'While critics praised the film's visuals, they panned its plot.' We can infer the critics found the film:

In 'The light dimmed', 'light' functions as a/an: