It"s a safe bet that David Joyce knows more than you did when you were his birth age. That"s not hard, since what you knew back then was pretty much nothing at all. You knew warmth, you knew darkness, you knew a sublime, drifting peace. You had been conceived 29 weeks earlier, and if you were like most people, you had 11 weeks to go before you reached your fully formed 40. It was only then that you"d emerge into the storm of stimuli that is the world. No such luck for David. He was born on Jan. 28—well shy of his April 16 due date—in an e-mergency cesarean(剖腹产的)section after his mother had begun bleeding heavily. He weighed 2 lb. 11 oz. , or 1,200g, and was just 15 in.(38cm)tall. An American Girl doll is 3 in.(8cm)taller. Immediately, he began learning a lot of things—about bright lights and cold hands, needle sticks and loud noises. He learned what it feels like to be hungry, to be frightened, to be unable to breathe. What all this meant was that if David wanted to stay alive, he"d have to work hard at it, and he was. Take drinking from a bottle—which he had never tried until a morning in late March, at the neonatal intensive care unit(NICU)of the Children"s Hospital of Wisconsin in Milwaukee. David had spent every day of his then seven-week life there, in the company of 58 other very fragile babies being looked after by a round-the-clock SWAT team of nearly 300 nutritionists, pharmacologists, pulmonary specialists, surgeons, nurses and dietitians and, for when the need arises, a pair of chaplains. Under their care, he had grown to 18. lin.(46cm)and weighed 51b. 11.5 oz.(2594g), nourished by breast milk from his mother, which was fed to him through a nasogastric tube(鼻胃管)threaded through his nose to his stomach. David"s father and mother live 90 minutes away in Randolph, Wis. They had been at the hospital every day after work for 51 days straight at that point—a three-hour round-trip—to spend a few more hours with David. What can be learned from the last paragraph