Exercise 4: Complete the sentences with relative pronoun: whom or which .   1. Tom made a number of suggestions, most of............ were very helpful.   2. Mart has three brothers, all of............... are married.   3. We were given a lot of information, most of................ was useless.   4. There were a lot of people at the party, only...........a few of I had met before.   5. I sent her two letters, neither of .............she has received.   6. I have two sisters, both of............... are doctors.   7. He lent me many picture-books, most of............... I had red.   8. The bur crashed into a queue of people. Four of ...............were killed.   9. He paid me $5 for cleaning ten windows, most of ..............hadn't been cleaned for at least a year.   10. In prison they fed us on dry bread, most of ..............was moldy.