（）John could not pass the final exam was once believed by all his roommates.

A．Something was wrong with the bus.
B．He took somebody to hospital.
C．Something prevented him taking the bus.
D．He came on foot instead of taking the bus.

A．Someone broke into the woman’s house and stole some jewels.
B．She knew how the burglars broke into her house.
C．She didn’t know what were stolen.
D．Policemen would arrive next day.