填空题 The hunter-gatherer tribes that today live like our prehistoric human 1ancestors consume primarily a vegetable diet supplementing with animal foods. 2An analysis of 58 societies of modern hunter-gatherers, including the Kung of southern Africa, revealed that one-half emphasize gathering plant foods, one-third concentrate on fishing, and only one-sixth are primarily hunters.Overall, two-thirds and more of the hunter-gatherer's calories come from 3plants. Detailed studies of the Kung by the food scientists at the University of London, showed that gathering is a more productive source of foodthan is hunting. An hour of hunting yields in average about 100 edible 4calories, as an hour of gathering produces 240. 5 Plant foods provide for 60 percent to 80 percent of the Kung diet, and no 6one goes hungry when the hunt fails. Interestingly, if they escape fatal infectionsor accidents, these contemporary aborigines live to old ages despite of the absence 7of medical care. They experience no obesity, no middle-aged spread, little dental decay, no high blood pressure, no heart disease, and their bloodcholesterol levels are very low(about half of the average American adult). 8If no one is suggesting that we return to an aboriginal life style, we certainly 9could use their eating habits as a model for healthier diet. 10