( ( ( Identify ( and ( research forces ) ) ) ( in ( nature ( such ( as ( ( gravity , ) ( electrical ( , ( magnetic forces ) ) ) ) ) ) ) ) ) ; )
(ROOT (NP (NP (NN Identify) (CC and) (NN research) (NNS forces)) (PP (IN in) (NP (NP (NN nature)) (PP (JJ such) (IN as) (NP (NP (NN gravity)) (, ,) (NP (JJ electrical) (, ,) (JJ magnetic) (NNS forces)))))) (: ;)))
Identify and research forces in nature such as gravity, electrical, magnetic forces;
(ROOT (S (NP (NNP Gravity) (CC and) (NNP magnetism)) (VP (VBP are) (NP (DT both) (JJ common) (NNS forces))) (. .)))
Gravity and magnetism are both common forces.