"<span>C. Is eighty-nine the best score so far?" is the only sentence in which the number is written correctly. In general, numbers in this way should have a hyphen between two different ones. </span>
Answer:
I think this book <u>is</u> too easy for me, so I don't think I'll read it.
Explanation:
i added the the word <em>"is"</em> to the sentence to make it complete.