She wondered whether ________ it be true.
She wondered whether ________ it be true.
Explanation
She wondered whether could it be true.
وہ حیران تھی کہ کیا یہ سچ ہو سکتا ہے۔
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"Could" is often used in conditional clauses
such as " someone thought about the true condition" so "could "is best to make a meaningful sentence