A．Because the dinner will be over in an hour.
B．Because he is iii and waiting for an operation.
C．Because he is attending his parents.
D．Because he has an urgent patient to deal with.

A．Because low-tar cigarettes are cheaper.
B．Because low-tar cigarettes reduce the risk to their health.
C．Because cigarette manufacturers have produced a lot of low-tar cigarettes.
D．Because the government advised people to buy low-tar cigarettes.