One similarity between the ancient civilizations in egypt and in china is that they developed

They both had settled communities - nothing nomadic in it. 
They both believed in numerous gods, including (sometimes) the Pharaoh or Emperor being considered divine. 
They had Pharaohs or Emperors, nothing democratic about it. 

That leaves you with written communication. 
A further similarity is, both used pictograms, not alphabets and phonetics (in other words they drew stylised images of what they were writing about, rather than write down the letters that allowed the spoken words to be pronounced). 
~o~ might mean "bird", while we write b i r d, or in some contexts it might mean flying.