The engineer __________my father works is about 50 years old.?

A.to whom            B.on whom            C.with which         D.with whom?

 My father is getting old. He needs a stick _______ to walk.

A. in which                                                      B. by which

C. with which                                                  D. with whom

The course normally attracts 20 students per year, _____ up to half are from abroad.

       A. of whom   B. for whom  C. in which  D. with whom

Many children，          parents are away working in big cities，are taken good care of in the village.

A. their                   B. whose

C. of them                 D. with whom

When she was alone at home，Mary needed a friend __________.?

A.playing with                                          B.having played with?

C.with whom to play with                   D.with whom to play?