If your field is Science and technology, background check is very possible. 
Why don't you apply for a AP to have a back-up.
回复:Advice Pls! Is this risky?
所有跟帖:
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                    risky. You were F1 and switched to H1.
                     -pharmacyelite- 
                    ♂                    
                        
                    
                                                            
                        
                    
                                        
                    
                    
                                        
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                        08/27/2007 postreply
                                                11:10:51