( ( From ( the ( tenth week ) ) ) ( ( the fetus ) ( ( begins ( to ( take ( on ( a ( human form ) ) ) ) ) ) . ) ) )
(ROOT (S (PP (IN From) (NP (DT the) (JJ tenth) (NN week))) (NP (DT the) (NN fetus)) (VP (VBZ begins) (S (VP (TO to) (VP (VB take) (PP (IN on) (NP (DT a) (JJ human) (NN form))))))) (. .)))
From the tenth week the fetus begins to take on a human form.
(ROOT (S (NP (NP (DT The) (NN development)) (PP (IN of) (NP (NP (DT the) (JJ respiratory) (NN system)) (PP (IN in) (NP (DT the) (NN fetus)))))) (VP (VBZ begins) (PP (IN at) (NP (QP (RB about) (CD 4)) (NNS weeks)))) (. .)))
The development of the respiratory system in the fetus begins at about 4 weeks.