The relatively few who use railways often are disproportionately well-off: three-fifths of the traffic is concentrated in the wealthy commuting counties of the south-east.
经常乘火车的人数相对较少，可是其中的富人比例却出奇地高，五分之三的列车集中于东南部的富人社区。
2
During what the safety board described as a 'concentrated period of discussion' neither pilot monitored the progress of the airplane nor air-traffic control communications.
Research in the area of bridge design has been and still is concentrated on the study of the strength of materials and relatively few studies have been performed on traffic loads and their effects.