I   How much do humen know about space now?

    A people know about 5 % of space          

         B 4 hundred billions of Galaxies (星系)

               C people drew pictures and made statues of alien long times ago

                    D Boriska –a boy from Mars

II   Hoax

     A  people start to disbelieve there are alien.

           B the people who made the hoax had been caught.

                C pictures

 III   Area 51

      A there are other area like area50 area49 but area 51 is the most famous.

          B where is area 51

             C pictures