For a start, they make air cleaner for us to breathe.

首先，它们使我们呼吸的空气更清新。

youdao

When we start to have a sense of offering a helping hand for a cleaner city and greener world, and when we have a loving heart to think more of others than of ourselves and are ready to help them, we can say that we have grown up.

我们有意识要帮助建设更清洁的城市和更绿色环保的世界，以及有爱心，多为他人着想，而不只是想着自己且乐意去帮助别人时，就可以说我们长大了。

youdao

He argues electric bicycles are safer than bicycles or motorcycles and will soon start using cleaner, lithium batteries.

他声称，电动自行车比普通自行车或摩托车都要安全，而且不久就将开始使用更清洁的锂电池。

youdao

It's very difficult to overtake the Red Bulls at the start but I'm on the cleaner side of the track so hopefully I can get a good start and jump the guy (Webber) on the outside who's on the dirty side.

BBC: European Grand Prix as it happened

By the final edition, the stories were far cleaner than at the start.

NEWYORKER: Once Upon a Time

We're also going to be talking about some developments we're making on biofuels, so that more folks can start filling up their cars and trucks with cleaner, American-grown fuels.

WHITEHOUSE: Meeting with Governors on Energy Policy