新英语四级改错练习题及答案精选四

　　Only a generation ago, Mauritanias capital city wasmany days 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 theeye can see.

　　In some parts of the Amazon rain forest in brazil, allthe 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 andvegetation necessary for life is disappearing. Already 5.__________more than 40 percent of the earths 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 tosurvive, but in difficulty. Now, largely through problems 7.__________caused by modern life, our existence is threatened by the 8.__________slow, steady spread of the earths deserts.

　　Many countries first became concerned in 1970s after 9.__________a terrible drought and famine destroyed Africas Sahel,the fragile desert along the south edge of the Sahara.

　　Thousands of people died even though there was a worldwideeffort to send food and medicine to the starved people. 10.__________参考答案1. days 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