6. The villagers, ______ had been damaged by the earthquake, were given help by the Red
 Cross. (      )
 A. all their homes                                    B. all whose homes
 C. all of whose homes                               D. all of their homes
 7. All ______ glitters is not gold. (      )
A. which                                                  B. who
C. /                                                          D. that
18. This tenth and last book of his ______ when he was bed-ridden. (      )
A. was written                                           B. were written
C. has been written                                    D. had been written
19. Each family ______ asked to plant a tree before summer came. (      )
A. is                                                         B. are
C. was                                                      D. were
20. I have both tea and coffee.______ do you prefer? (      )
 A. Which                                                B. What
 C. Which one                                          D. What one