The distance from the airport to the center of Sydney is______.

A．Volcanic eruptions.
B．Mountain torrents.
C．Crop and livestock production.
D．The floods after the storm.

A．How to make the coronary bypass operation.
B．An objective introduction of the coronary bypass operation.
C．The controversy within the medical profession on the coronary bypass procedure.
D．A complete refusal of coronary bypass operation