题目

书面表达。 请根据提示写一篇题为The Population Problem的短文。（80词左右） 提示: 1.人口问题是当今世界上最大的问题之一； 2.中国是世界上人口最多的国家； 3.如果人口增长过快，将会带来许多严重问题（请举例说明）； 4.我们应继续执行计划生育政策，以控制人口增长。 答案：THE POPULATION PROBLEM There are more and more people in the world. There is less land for people to live. The environment will be terrible. Many trees will be cut down. Good land will be lost. Crops will not grow well. We will be short of food. It is difficult for people to find work. How do they afford their children? We have to think about these problems. Thanks to our government, we carr锌不但能与稀硫酸反应，还能与浓硫酸反应，现有一定质量的锌与浓硫酸在密闭器内发生反应，测得反应前后各物质的质量如下表所示，则下列有关X的说法中，正确的是物质ZnH2SO4H2OZnSO4X反应前质量（g）10.048.02.000反应后质量（g）3.528.45.616.1xA.X一定是催化剂B.X可能是催化剂C.X中含有锌和硫元素D.X中硫元素质量分数为50.0%