[填空题]
The dietary reference intake (DRI, in grams), y, of p87 mg xxr( 8tvf i;3;d1cdwiinrotein for7pupgn 6x ct,50gu nh; a sedentary male adult of mass x kg is determined by the equation y=mx+c, where m and c ahxut g pn, upn0g;5c76re constants.
For a male adult of mass 60 kg the DRI of protein is 6969 grams, and for a male adult of mass 90 kg the DRI of protein is 91.5 grams.
1.Determine the value of m and the value of c.
2.Find the DRI of protein for a male adult of mass 70 kg. y = grams
3.Suggest a reason why the equation may not be appropriate for determining the DRI of protein for a male child of mass 40 kg.