A rapid change is one that happens very quickly.
the country's rapid economic growth in the 1980s.
这个国家在20世纪80年代快速的经济增长。
the rapid decline in the birth rate in Western Europe.
西欧人口出生率的快速下降。
A rapid movement is one that is very fast.
He walked at a rapid pace along Charles Street.
他沿着查尔斯大街快步行走。
The Tunnel will provide more rapid car transport than ferries.
隧道将提供比轮渡更快速的车辆运输。