The hunter-gatherer tribes that today live as our prehistoric human __1__
ancestors consume primarily a vegetable diet supplementing with animal foods __2__
An analysis of 58 societies of modern hunter-gatherers, including the Kung of
southern Africa, revealed that one-half emphasize gathering plants 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 __3__
plants. Detailed studies of the Kung by the food scientists at the University
of London, showed that gathering is a more productive source of food
than is hunting. An hour of hunting yields in average about 100 edible __4__
calories, as an hour of gathering produces 240. __5__
Plant foods provide for 60 percent to 80 percent of the Kung diet, and no __6__
one goes hungry when the hunt fails. Interestingly, if they escape fatal infections
or accidents, these contemporary aborigines live to old ages despite of the absence __7__
of medical care. They experience no obesity, no middle-aged spread, little
dental decay, no high blood pressure, no heart disease, and their blood
cholesterol levels are very low (about half of the average American adult). __8__
If no one is suggesting that we return to an aboriginal life style, we certainly __9__
could use their eating habits as a model for healthier diet. __10__

参考答案及解析:

1. 将as 改为like
此处的意思是“像史前人类祖先那样生活”。

2. 将supplementing改为supplemented
supplemented 修饰diet，可以看作which is supplemented with animal foods的简化形式。

3. 将and 改为or

4. 将in改为on
on average 是固定用法。

5. 将as 改为while或者whereas

6. 删掉for，或者将provide改为account
此处provide 是及物动词，后面不用介词for

7. 删掉第一个of
despite 做介词，后面直接接名词。

8. 在half后加that
that 指代前面的blood cholesterol levels，不能省略，因为这里是将部落成员的胆固醇含量与美国人的胆固醇含量相比较。

9.将if改为whereas或者while
此处意思为“尽管没有人……,但是……”，是转折关系。

10.在for后面加不定冠词a。