我们城市的以前不太。
The air in our city used to be not very clean.
很多车每天在路上跑，让变得更差。
Many cars drive on the roads every day, making the air worse.
后来，开始让大家多坐和。
Later, the government began encouraging people to take the subway and buses more.
很多人也开始骑上班。
Many people also started riding bicycles to work.
公园里种了更多的树和花。
More trees and flowers were planted in the parks.
现在，城市的比以前好多了。
Now, the city's environment is much better than before.
天空也变蓝了，更了。
The sky has turned bluer and the air is fresher.
需要每个人一起。
Protecting the environment requires everyone to work together.