He paid the boy $ 10 for washing ten windows, most of ____ hadn't been cleaned for at least a year.

   A. these           B. those           C. that             D. which

He paid the boy $10 for washing ten windows, most of ________hadn't been cleaned for at least a year.

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He paid the boy $10 for washing ten windows, most of ________ hadn't been cleaned for at least a year.

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He paid the boy $ 10 for washing ten windows , most of ________ hadn’t been cleaned for at least one year.

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