I think our environment is not very good. The air is dirty, the sky is not blue everyday and the rivers are polluted.

我认为我们的环境不太好。空气不干净。天也不是每天都很蓝。河流被污染了。

youdao

In severe winter, the air is dirty and the amount of exercise is also greatly reduced because people often stay indoors and seldom open the door and Windows.

严冬时，由于人们常在室内，又很少开门窗，故空气污浊，活动也大减少。

youdao

Which is considered a weakness of the city-level measures to tackle dirty air?

哪些被认为是城市层面应对空气污染措施的不足之处？

youdao

Air pollution is another serious problem: the sky above the Strip is sometimes so dirty that you cannot see the mountains for the haze.

BBC: Discover life in the Nevada desert