Research on the language capabilities of apes clearly demonstrates that they have the capacity to

The answer would be: communicate through the use of symbols.
In term of social hierarchy and communication, apes displayed some facinating simarties with human.
Up to this day, we already find out that apes use approximately around 350 sign languages in order to operates within their social groups

The correct answer is "the protesters were attacked by chinese troops and many were killed or arrested."