题目

如图是某同学整理的铁及其化合物知识网络图。（1）用数字和符号表示：①金属铁中铁元素化合价_____②氯化铁中的阳离子_____。（2）向少量铁锈中加入足量稀硫酸中，反应的现象是_____。（3）暖宝宝中的主要成分是炭粉、铁粉、氯化钠，利用铁粉在空气中发生了缓慢氧化变成铁锈，而放出热量，其中氯化钠的作用为_____。（4）服用FeSO4补充铁元素，可以预防_____（填序号）。A 贫血 B 骨质疏松 C 甲状腺疾病 D 侏儒症Fe FeSO4，则甲物质的类别可能属于____根据短文内容，从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。Since the day of its birth, the United Nations has been the subject of much debate.1. Others think that it is too weak. We can better understand this debate if we learn more about the U.N. and its history.The U.N. was started for two reasons. First, when the idea was born, people all over the world were tired of war. They felt that there must be peaceful answers to the world’s problems.2. The second reason was that modern science had developed new bombs and airplanes.3. National borders were beginning to lose their meaning. Science would develop even more dangerous weapons in the future. Only an international organization would be able to control modern science.Franklin D. Roosevelt, U.S. President at the time, believed that the Allies (联盟) should plan for peace before the war ended. On December 1, 1943, Roosevelt, Britain’s Winston Churchill and Joseph Stalin from Soviet Union agreed to start an organization for world peace.4. During the next year and a half, the idea of such an organisation was debated around the world. Then came the big day. On April 11, 1945, the first international meeting of the United Nations took place in San Francisco. The goal of the meeting was to write the U.N. Charter (宪章). All of the fifty-one nations at the meeting had their own ideas to offer for the Charter.5. Every nation present voted for the Charter. No one voted against it.A. The U.N. Charter is a beautiful piece of writing.B. After a long debate, a final Charter was agreed upon.C. Even the smallest country on earth can have its voice heard.D. They asked all countries, large and small, to join the organization.E. These weapons made it almost impossible for a country to defend itself.F. Some people attack the organization because they think it is too powerful.G. They also felt that only an international organization could keep world peace.