Final answer:
The sentence 'I can’t stand (a) _________ in a long queue' should be completed with the reflexive pronoun 'standing' to reflect that the subject 'I' is the same as the object.
Step-by-step explanation:
The sentence should be completed with a pronoun that fits the context. In this case, the correct answer is the reflexive pronoun 'standing' because it refers back to the subject 'I.'
Therefore, the complete sentence is 'I can’t stand standing in a long queue.' Reflexive pronouns are used when the subject and the object of the sentence are the same, and in this sentence, the person who can't stand is the same person who would be standing in the queue.