题目

阅读理解Young people in China are more optimistic (乐观的) than those in othercountries, according to a survey. It asked 200,000 young people in 20 countrieshow they think and feel about the world. These countries include China, the US,the UK and so on. The survey found that 53 percent of Chinese youth think theworld is becoming a better place.When asked why they felt hopeful for the future, most of them think it'sbecause of high technology (科技), many of them also thinkChina is a good place to live in. The biggest reason is that China is acountry in which anyone can make their dream3．某溶液中可能存在Br-、CO32-、SO32-、Al3+、I-、Mg2+、Na+、K+等8种离子中的某几种．取该溶液进行实验，得到如下现象：（　　）①向溶液中滴加过量氯水后，溶液变橙色，且有无色气泡冒出；②向所得橙色溶液中加入足量BaCl2溶液，无沉淀生成；③向所得溶液中继续滴加淀粉溶液，溶液不变蓝色．据此可以推断：该溶液中存在的离子组可能是．A．Al3+、Mg2+、SO32-B．K+、CO32-、I-C．Al3+、CO32-、I-D．Na+、Br-、CO32-