Directions: Choose the word for the given options that could fit in the blank…

In a sentence-completion item joined by a contrast connector such as 'but', the missing word is normally chosen so that it sets up the sharpest, most idiomatic before-and-after contrast with the clause that follows it — not merely any grammatically compatible positive word. Vocabulary-in-context items of this kind test recognition of that best-fitting, most natural collocation, which is usually anchored to an established, source-verified usage of the word rather than any word that is merely not ungrammatical.

Here the second clause — 'but in recent weeks it has begun to have problems' — signals a company that recently started to falter after an earlier period of apparent strength. 'Invincible' means too powerful to be defeated, destroyed, or overcome, and is the standard way to describe something that seemed unstoppable; pairing it with 'but ... problems' creates the classic ironic reversal ('seemed unbeatable, yet stumbled') that this kind of sentence is built to deliver. This is confirmed directly by the source: this sentence is adapted from the Cambridge Dictionary's own example sentence for the word 'invincible' ('Last year the company looked invincible but in recent weeks has begun to have problems') — wording chosen by lexicographers specifically to demonstrate 'invincible', which settles which word was intended here.

• 'Incomprehensible' describes something impossible to understand or make sense of — a property of clarity, not of strength or dominance — so it does not build the intended before-and-after contrast.

• 'Incorrigible' describes a persistent bad habit that cannot be corrected — itself a negative quality — so it cannot represent an earlier positive state that later 'began' to run into problems.

• 'Impartial' describes something free from bias, favouring no side unfairly — a property of fairness, not of strength or dominance, so it does not build the intended before-and-after contrast.

• 'Impossible' describes something that cannot occur or be done — a property of feasibility, not a quality that describes how a company 'looked' in a given year.

The word that completes the sentence with the intended sharp contrast is therefore 'invincible'.