The engineer ________ my father works is about 50 years old.
A．to whom B．on whom
C．with which D．with whom
They arrived at a farmhouse，in front of ________ sat a small boy.
A．whom B．who C．which D．that
The pen ________ he is writing is mine.
A．with which B．in which
C．on which D．by which
Can you lend me the book ________ the other day?
A．about which you talked B．which you talked
C．about that you talked D．that you talked
At the party，John made up a joke，________ people burst out laughing.
A．on which B．by which C．at which D．from which
That is the day ________ I'll never forget.
A．which B．on which C．in which D．when
