... can be a lot like mazes. Both above and below ground,cities, especially very old ones, are home to interesting...
MRT=Mass Rapid Transit, which is not always or necessarily under the ground. You can use "the SUBWAY" or "the TUBE", which is usrely under the ground.
...面之分隔線)--------------- below 在下面,有接觸的 ex: The basement is below the ground floor. (以整個空間或範圍來說) under 在底下,沒有接觸到的 ex: My eraser...