( ( In ( a ( developing fetus ) ) ) ( , ( cartilage ( ( becomes ( impregnated ( with ( deposits ( of ( calcium salts ) ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (IN In) (NP (DT a) (VBG developing) (NN fetus))) (, ,) (NP (NN cartilage)) (VP (VBZ becomes) (VP (VBN impregnated) (PP (IN with) (NP (NP (NNS deposits)) (PP (IN of) (NP (NN calcium) (NNS salts))))))) (. .)))
In a developing fetus, cartilage becomes impregnated with deposits of calcium salts.
(ROOT (S (ADVP (RB Early) (PP (IN in) (NP (NP (DT the) (NN development)) (PP (IN of) (NP (DT a) (JJ human) (NN fetus)))))) (, ,) (NP (DT the) (NN skeleton)) (VP (VBZ is) (VP (VBN made) (ADVP (RB entirely)) (PP (IN of) (NP (NN cartilage))))) (. .)))