A．The sanitary conditions of an apartment.
B．The janitor is too busy to do his work.[C] The relationship between the janitor end the .two speakers.
C．The architecture of a building.

A．Computers may change the life they have been accustomed to.
B．Spending too much time on computers may spoil people’s relationship.
C．Buying computers may cost a lot of money.
D．Computers may take over human beings altogether.