1·It frequently contributes to the smogs over Los Angeles.
同时它也常常引起洛杉矶上空的烟雾。
2·First: "It's only nature, we've always had smogs, what's the big deal?"
第一：“那是自然的事情，我们一直有雾，有什么大不了的？”
3·Vehicles also cause air pollution, which produces city smogs, acid rain, and global warming.
交通工具也能造成空气污染，这种污染也产生了城市烟雾，酸雨和全球变暖。