( ( Perform ( ( a skit ) ( which ( ( explains ( ( the theory ) ( of ( biological evolution ) ) ) ) ( through ( natural selection ) ) ) ) ) ) . )
(ROOT (S (VP (VB Perform) (NP (NP (DT a) (NN skit)) (SBAR (WHNP (WDT which)) (S (VP (VBZ explains) (NP (NP (DT the) (NN theory)) (PP (IN of) (NP (JJ biological) (NN evolution)))) (PP (IN through) (NP (JJ natural) (NN selection)))))))) (. .)))
Perform a skit which explains the theory of biological evolution through natural selection.
(ROOT (S (NP (NP (NNP Theevolution)) (PP (IN by) (NP (JJ natural) (NN selection) (NN theory)))) (VP (VBZ explains) (SBAR (WHADVP (WRB how)) (S (NP (NP (NNS populations)) (PP (IN of) (NP (NNS organisms)))) (VP (MD can) (VP (VB change) (PP (IN over) (NP (NN time)))))))) (. .)))