Help -- Importing ontology in alternative way

Hello experts,

I would like to import ontoloies from local disk when internet
connection is not available.
So I want to add alternative uri on importing clause. 
If it is possible, please give me any comment.
I appreciate any comment.
Thank you so much in advance,

Paul

<owl:Ontology rdf:about="">
    <owl:imports>
        <rdf:Alt >
           <rdf:li rdf:resource="http://my.ontology.com/MyOntology.owl"/>
           <rdf:li rdf:resource="file:///C:/ontology/MyOntology.owl"/>
        </rdf:Alt>
     </owl:imports>
  </owl:Ontology>