Many people believe building an underground city is one way to alleviate the problem.
许多人认为，建造地下城市是减缓该问题严重性的一种方法。
The city planner decided to build an underground drainage system.
城市规划师决定建一个地下排水系统。
This street is the first in the city to have an underground sewer system.
这条街是本市第一条有下水道系统的街。
This street is the first in the city to have an underground sewer system.
这条街是本市第一条有下水道系统的街。
应用推荐