Newbie Query

Hi,
 
Anyone who knows answers to these questions please let me know.
 
Q. Can a SOAP message carry messages from two distinct operations? Does the
standard say anything on this?
Q. Can more than one <operation> in < PortType> WSDL refer to same
<message>? If yes, then how does the
    receiver distinguish which operation was invoked?
 
Please provide some relevant pointers.
 
Thanks
Ashish