{{i}}quEstions 17 - 20 ArE BAsED on thE Following tAlk. you now hAvE 20 sEConDs to rEAD quEstions 17- 20.{{/i}}

in ForEsts, ChimpAnzEEs spEnD muCh oF thEir timEA．in trEEs.
B．wAlking on All Fours.
C．wAlking on thEir hinD lEgs.
D．Fighting to kEEp thEir groups From BEing BrokEn up.