原级：roundabout
1. Sufficient roundabouts have proved effective in ensuring traffic does not come to a grinding stop for long periods at key intersections.
2. roundabouts
2. As the old saying goes, 'what you lose on the swings you gain on the roundabouts'.
3. The importance of doing away with roundabouts and expanding road network is evident on the superhighway.
4. Another method popular in most Western countries to keep traffic flowing is to replace traffic lights with roundabouts.