cardboard city

例句：

1. 1. The city has been redeveloping its old buildings into new ones using cardboard.
   这个城市正在用纸板改造旧建筑，建造新的。
2. 2.The cardboard city is a symbol of the city's efforts to reduce waste and pollution.
   纸板城市是该市减少浪费和污染努力的象征。
3. 3. The cardboard city is a popular destination for tourists who want to experience the city's unique architecture.
   纸板城市是那些想体验城市独特建筑的游客的热门目的地。