( ( ( White cells ) ( -LRB- ( leukocytes -RRB- ) ) ) ( ( are ( ( the ( protective cells ) ) ( in ( the ( blood stream ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNP White) (NNS cells)) (PRN (-LRB- -LRB-) (NP (NNS leukocytes)) (-RRB- -RRB-))) (VP (VBP are) (NP (NP (DT the) (JJ protective) (NNS cells)) (PP (IN in) (NP (DT the) (NN blood) (NN stream))))) (. .)))
White cells (leukocytes) are the protective cells in the blood stream.
(ROOT (S (NP (JJ Leukocytes) (NN blood) (NNS cells)) (VP (VBP are) (ADJP (JJ white))) (. .)))