原级：footbridge
1. footbridges
1. When the MTR opened in 1979, footbridges became a popular tool to connect stations to surrounding housing estates and shopping malls.
2. Xiao Yan said bamboo could cut the cost of footbridges in cities and bridges in the countryside by half.
3. footbridges的解释
3. " There's little distinction between being on the ground and being on the footbridges, " says Solomon.
4. The brook is spanned by nearly 50 footbridges and tickles the doorsteps of riverside houses.