Combine the following pair of sentences into one sentence by subordinating information about one of the nouns or verbs.Igor Sikorsky was born in...

Think of subordinate information of information that is of
secondary importance in the sentence(s).  So your first step is to determine a hierarchy
of importance between the facts presented in the statements.  The part that is of least
importance should be surrounded by commas. 

The most
important thing about Skorsky is that he invented the helicopter because that is what
made him famous; therefore, the information about where and when he was born is the
subordinating information.  The sentences should be combined like
this:

Igor Sikorsky, who in 1885 was born in Kiev, Russia,
invented the helicopter.