It looks like they are grafted.... I bought one too and it was in the same condition as yours. Unwrap the plastic and see if it is a graft or no. there is no other way to make sure.
Grafted trees have two part the graft and the rootstock they are different plants joined together because of wanted characteristics of the rootstock and the upper plant I think it is called scion in english.

Hi mohamad,thank u so much for answering,and is good to know that according to you they look like grafts!!!I,ll remove the plastics to see if it's possible to look the two different parts together,thank u so much again!!!

Glad I was able to help!
Good luck with them, they are slow growers by the way.
I saw a grafted one bear fruit while it was the plant was the size of about two feet. Good luck!