( ( An asteroid ) ( ( ( ( ( six to ) 10 ) miles ) across ) ( ( ( ( ( collided ( with ( the Earth ) ) ) ( ( ( about ( 65 million ) ) years ) ago ) ) and ) ( is ( thought ( to ( have ( caused ( ( the extinction ) ( of ( ( ( the dinosaurs ) , ) ( along ( with ( ( 75 percent ) ( of ( all ( other species ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) . ) ) )
(ROOT (S (NP (DT An) (NN asteroid)) (ADVP (NP (QP (CD six) (TO to) (CD 10)) (NNS miles)) (IN across)) (VP (VP (VBD collided) (PP (IN with) (NP (DT the) (NN Earth))) (ADVP (NP (QP (RB about) (CD 65) (CD million)) (NNS years)) (RB ago))) (CC and) (VP (VBZ is) (VP (VBN thought) (S (VP (TO to) (VP (VB have) (VP (VBN caused) (NP (NP (DT the) (NN extinction)) (PP (IN of) (NP (NP (DT the) (NNS dinosaurs)) (, ,) (ADVP (IN along) (PP (IN with) (NP (NP (CD 75) (NN percent)) (PP (IN of) (NP (DT all) (JJ other) (NN species)))))))))))))))) (. .)))
An asteroid six to 10 miles across collided with the Earth about 65 million years ago and is thought to have caused the extinction of the dinosaurs, along with 75 percent of all other species.
(ROOT (S (PP (IN In) (NP (DT the) (NN past))) (, ,) (NP (NP (NNS asteroids)) (VP (VBG colliding) (PP (IN with) (NP (NN planet) (NN earth))))) (VP (VBZ has) (VP (VBN caused) (NP (JJ many) (NNS organisms)) (S (VP (TO to) (VP (VB die) (PRT (RP off))))))) (. .)))