Job Recruitment Website - Zhaopincom - (2005? Heze) Calcium in human body mainly exists in bones and teeth in the form of calcium hydroxyphosphate crystals [Ca5(PO4)3(OH)], among which

(2005? Heze) Calcium in human body mainly exists in bones and teeth in the form of calcium hydroxyphosphate crystals [Ca5(PO4)3(OH)], among which

The mass fraction of calcium in (1) hydroxyapatite is 40× 540× 5+(31+16× 4 )× 3+(16+1)×1× 60.

(2) The daily calcium requirement of human body from milk is at least 0.6g×90%=0.54g,

0.54g (0. 1 1×2.5)≈2

Therefore, two boxes are needed.

So the answer is:

( 1)39.8%;

(2)2.