If someone becomes Europe citizen (By marrying an european citizen), can he/she become a us citizen, too?

While the US does not recognize dual citizenship., the US does permit a person to hold more than one citizenship.

Hello my friend is visiting the states on a tourist visa, can she apply for work visa?

If there is a basis that fits one of the visa classifications that permit employment

Can I have two sponsors for my marriage?

Yes you may have more than one but one must meet the requisite income requirement.

Why does it says my address was changed relating to my i130 application for spouse?

You can contact CIS customer service or send a note correcting.

How long can I stay in US if i withdraw RFE reply which is due by 11.30.2014?

Employer's decision to reply or not reply. Withdrawal ends your stay in the US.

You cannot tell by an officer's demeanor you will need to wait for a decision.

J 1 waiver - different application. Same case numbers ?

You do not need to provide a case number, although you may want to refer to the prior filings.

Green Card

If the Foreign National has obtained resident status based on a bona fide relation and the condition has been removed, nothing happens

Employment contract

This is an employment contact question and you should direct to an employment attorney. As to immigration aspects, the employer is responsible to...

The consulate does not believe the person is coming as a valid K visa holder.