作例4 89p テキストの一部を隠す(1)

作例⑧ p. 98
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Over 70 percent of the surface of the earth is covered with
water. That is why the earth is called the “water planet.” As
you can see on this chart, however, the water available for
human use is only about 0.03 percent of the total amount of
the earth’s water. More than seven billion people and all other
animals and plants must share this limited resource.