Answer :
Final answer:
The underlined auxiliary verb that helps express the subjunctive mood is 'could.'
Explanation:
The underlined auxiliary verb that helps express the subjunctive mood is 'could' in the sentence 'If the future could be clear, we would prevent all weather-related accidents.' The subjunctive mood is used to express hypothetical situations, wishes, or conditions that are contrary to reality. In this example, the use of 'could' suggests a hypothetical future where the clarity of the future is uncertain.
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