1.   Her friends gave her encouragement. I’d like to be one among them.           (who)

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2.   She sold her car last year. She had driven it for over twenty years.     (which)

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3.   I was sitting on a chair. It suddenly collapsed.                                                  (which)

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4.   Mr. Smith was too busy to speak to me. I came to see him.               (whom)

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