Is it possible?

No, a person can only have one Devil's fruit ability. This was mentioned in the Ennis Tower Arch of One Piece. Something about "the devil's fighting" or mixing inside them. It would be incredibly OP if that was true. We'll just have to wait to see how the plot twist goes.

yeah. one question.. maybe i missed it or didn't understand but how come blackbeard have Whitebread's power?

Oh yeah I forgot about him, that's true. You're clever. Although so far Black Beard is the first and only with two devil fruit abilities. However if they start introducing the two devil fruit thing with Law and make it become more common, I feel that it will loose a lot of purpose. The issue with Black Beard has not been explained yet, so no need to be confused, you didn't miss anything.

No Marco, from the white beard pirates said that black beard has an "a typical body structure" or something

Yes and remember what Luffy and Zorro said after they meet with Blackbeard, they said 'It's not him but they,' So I think there something different about Blackbeard.. And we still don't know what that 'thing' is.

Ahh..., this manga is way too long to reach their ending.

no,, 'It's not him but they,' I think that luffy and zoro knew that teach wasn't alone, he had a crew at that time, so that's why luffy and zoro refer him as they..

i think when him in the room, he can do anything like when he sent a message to chopper when luffy and tragay got caught.. telephaty is possible too

its because his "D." people with "D." have a power to against god..

so that means... Luffy can also eat more than one devil fruit??

no, the devil fruil that can absord other devil fruit powers is yami yami no mi and if people with "D." (with typical body structure) ate the yami yami no mi, he can have two devil fruit.. jinbe had said "luffy you must careful because blackbeard search people with strong devil fruit" (fishmen island arc) that means blackbeard can have more than two devil fruit power..