part Ⅱ proofreading and error correction （15 min）
the following passage contains ten errors. each line contains a maximum of one error. in each case, only one word is involved. you should proofread the passage and correct it in the following way. for a wrong word, underline the wrong word and wri te the correct one in the blank provided at the end of the line. for a missing word, mark the position of the missing word with a “∧” sign and write the word you believe to be missing in the blank provided at the end of the line. for an unnecessary word cross out the unnecessary word with a slash “/' and put the word in the blank provided at the end of the line.
example
when∧art museum wants a new exhibit, （1） an
it never／ buys things in finished form and hangs （2） never
them on the wall. when a natural history museum
wants an exhibition, it must often build it. （3） exhibit
the hunter-gatherer tribes that today live as our prehistoric 1.___
human ancestors consume primarily a vegetable diet supplementing 2.___
with animal foods. an analysis of 58 societies of modem 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 plants. detailed 3.___
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 4.___
edible calories, as an hour of gathering produces 240. 5.___
plant foods provide for 60 percent to 80 percent of the kung 6.___
diet, and no 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 of medical care. 7.___
they experience no obesity, no middle-aged spread, little dental
decay, no high blood pressure, on heart disease, and their blood
cholesterol levels are very low（ about half of the average american 8.___
adult）, if no one is suggesting what we return to an aboriginal life 9.___
style, we certainly could use their eating habits as a model for 10.___
healthier diet.