adsense cpm

Hi, as an adsense publisher I want to know if I have the choice of only having ads on my site on a per impression basis instead of cost per click basis?

Also does anyone know which which makes more money? cpc or cpm on adsense?

also for global worldwide traffic, what kind of cpm is expected for adsense

you cant choose cpm ads alone,

CPC is more than CPM. most of the cases.