问题补充：
短文改错﹙10分﹚
Though great progress have been made in science these years, there are still many people live in poor conditions. They make their lives by collecting or selling used things. Their children cannot go to school because they had not enough money to send their children there. How do you think so many people still suffer from poverty now? The answer lies on the population explosion﹙人口大爆炸﹚. A president of a developing country once said, “It is us who are to blame for the poverty because we used to ‘produce’ child without limit.” Although this few words sound simple enough, they have clear pointed out one of the causes of the population explosion.【小题 1】have—has
答案：
(答案→)【小题 1】have—has
解析：
【小题 1】progress 三人称单数，have—has
【小题 2】生活很贫困的人们。living 现在分词短语作后置定语，修饰people.
【小题 3】and 并且，表顺承关系。捡破烂并且卖掉。
【小题 4】had—have一般现在时
【小题 5】How — Why 为什么；根据后文the answer 可知。
【小题 6】lie in 存在于；lie on 依赖，取决于
【小题 7】us—we强调句型 It is + 被强调部分+ who…
【小题 8】children 孩子们
【小题 9】these 这些话，表复数的概念。
【小题 10】clearly 清楚地，副词修饰动词，形容词修饰名词。此处clearly修饰have pointed out.
