( ( ( A ( 24-hour period ) ) ( during ( which ( ( the earth ) ( completes ( one rotation ) ) ) ) ) ) . )
(ROOT (NP (NP (DT A) (JJ 24-hour) (NN period)) (PP (IN during) (SBAR (WHNP (WDT which)) (S (NP (DT the) (NN earth)) (VP (VBZ completes) (NP (CD one) (NN rotation)))))) (. .)))
A 24-hour period during which the earth completes one rotation.
(ROOT (S (NP (PRP It)) (VP (VBZ takes) (NP (NP (CD 24) (NNS hours)) (PP (IN for) (NP (DT the) (NN earth) (S (VP (TO to) (VP (VB make) (NP (NP (DT a) (JJ complete) (NN rotation)) (PP (IN of) (NP (PRP$ its) (NNS axis))))))))))) (. .)))