[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