( ( Describe ( ( the sequence ) ( of ( events ( in ( ( the ( immune system ) ) ( when ( ( the body ) ( first ( encounters ( a pathogen ) ) ) ) ) ) ) ) ) ) ) . )
(ROOT (S (VP (VB Describe) (NP (NP (DT the) (NN sequence)) (PP (IN of) (NP (NP (NNS events)) (PP (IN in) (NP (NP (DT the) (JJ immune) (NN system)) (SBAR (WHADVP (WRB when)) (S (NP (DT the) (NN body)) (ADVP (RB first)) (VP (VBZ encounters) (NP (DT a) (NN pathogen))))))))))) (. .)))
Describe the sequence of events in the immune system when the body first encounters a pathogen.
(ROOT (S (NP (DT The) (JJ innate) (JJ immune) (NN system)) (VP (VBZ serves) (PP (IN as) (NP (NP (DT a) (JJ first) (NN responder)) (PP (TO to) (NP (NP (JJ pathogenic) (NNS threats)) (SBAR (WHNP (WDT that)) (S (VP (VB bypass) (NP (NP (JJ natural) (ADJP (NN physical) (CC and) (NN chemical)) (NNS barriers)) (PP (IN of) (NP (DT the) (NN body)))))))))))) (. .)))