[填空题]
Now we travel to the north central part of the United States.
We are in the state of South Dakota. The land is big and mostly fiat with many
{{U}} (36) {{/U}}of corn, wheat and soybeans. But as we travel west, the
cropland gives way to wild grasses. A strong dry wind blows {{U}} (37)
{{/U}} from the west.
Suddenly, the land becomes
{{U}} (38) {{/U}} and rocky, dry and dusty--no longer green and gold. It
is now a light red-brown color. All around are broken {{U}} (39) {{/U}}
forms. There are hills and valleys of all sizes and strange shapes.
These are the Badlands. Hundreds of thousands of years ago the area was
{{U}} (40) {{/U}}, but, then, forces of nature {{U}} (41) {{/U}}
the grass. Water and ice cut into the surface of the earth. They heat at the
rocks, {{U}} (42) {{/U}}them away. The result is one of the world’s
{{U}} (43) {{/U}} sights.
{{U}} (44)
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The area is a study in extremes. Temperatures in
[单项选择]Wang Lin is a 12-year-old girl in the north part of China. It is (41) for her family to get clean water. The nearest place to get water is a dirty hole half a kilometer from their (42) .
Every morning, Wang Lin (43) home at half past five to get water for her family. Sometimes it (44) six hours to get enough clean water. Wang Lin has no time to go to school (45) play with her friends.
Millions of people in the world (46) Wang Lin. They can’t get enough clean water to keep (47) . Most of those people are in the north part of China.
Water covers 70 per cent of Earth’s surface. But most of that is sea water. We can’t use it directly in many ways. Fresh water is (48) we use to drink, take showers and cook food. And fresh water (49) only 1 per cent of Earth’s surface.
Many people have made wells to get clean water from (50) . But there still isn’t enough. Scientists say that in 30 year
