During experiments in captivity, <e1>capuchins</e1> have made flint <e2>knives</e2> after banging a piece of flint against the floor until it broke.
During experiments in captivity,
During experiments in captivity, capuchins have made flint knives after banging a piece of flint against the floor until it broke.
<triplet> capuchins <subject> knives <object> Product-Producer(e2,e1)