<span>As periods in mathematics we call groupings of large numbers (three-digits) usually separated by comma or space.
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In this particular case we got two periods: 913 and 256.
Digits 913 are in the thousands period, while 256 in the units period.
The sentence that the pronoun comes before the antecedent is: His reputation was Tom's greatest possession. The correct answer is option C. The pronoun used in the sentence is "His" and the antecedent referred by the pronoun "his" is the noun "Tom".
It’s blur and i can’t help :/