what are objects that are streamlined and what are the advantages?

Answer 1

Images of streamlined vehicles:
http://images.google.com/images?q=streamlined%20vehicles&rls=com.microsoft:en-us:IE-SearchBox&oe=UTF-8&sourceid=ie7&rlz=1I7SUNA_en&um=1&ie=UTF-8&sa=N&tab=wi

Definition -- with reasons why streamlining vehicles (cars, boats, planes, trucks, etc.) as much as possible is advantageous:
http://www.answers.com/topic/streamline