英语四级考试辅导：改错精练（4）

　　Only a generation ago, Mauritania's capital city was
　　many day's walk from the Sahara. Today it is in the Sahara. 1.__________
　　The sand blows through the city streets and piles up in 2.__________
　　walls and fences. The desert stretches out as far as the
　　eye can see.
　　In some parts of the Amazon rain forest in brazil, all
　　the trees have cut down. The earth lies bare and dry in the 3.__________
　　hot sun. Nothing grow there anymore. 4.__________
　　Over vast areas of every continent, the rainfall and
　　vegetation necessary for life is disappearing. Already 5.__________
　　more than 40 percent of the earth's land is desert and 6.__________
　　desert-like. About 628 million people--one out of seven--
　　live in these dry regions. In the past, they have managed to
　　survive, but in difficulty. Now, largely through problems 7.__________
　　caused by modern life, our existence is threatened by the 8.__________
　　slow, steady spread of the earth's deserts.
　　Many countries first became concerned in 1970s after 9.__________
　　a terrible drought and famine destroyed Africa's Sahel,
　　the fragile desert along the south edge of the Sahara.
　　Thousands of people died even though there was a worldwide
　　effort to send food and medicine to the starved people. 10.__________
　　参考答案
　　1. day's → days'
　　2. in → against
　　3. have ∧ cut → been
　　4. grow → grows
　　5. is → are
　　6. and → or
　　7. in → with
　　8. our → their
　　9. in ∧ 1970s → the