How about Xiaomi's car air purifier?

A. 1

It's cost-effective.

Gentleman 8 years ago 0

OK

A. 2

The air purifier itself is not so good at cleaning air.
Opening and ventilating windows makes the air faster and more effective.

Gentleman 8 years ago 0

OK

A. 3

I agree with number two.
The ability of the air purifier we hear is the ability of marketing.

Gentleman 8 years ago 0

OK