题目

The global financial crisis, ______ started in the USA in 2008, affects almost every country, especially some developed countries. A. what         B. it           C. which        D. that 答案：C4．下列可用来区别SO2和CO2气体的是 （　　）①澄清的石灰水  ②氢硫酸  ③氯水  ④酸性高锰酸钾  ⑤品红溶液  ⑥氯化钡．A．①④⑤⑥B．②③④⑤C．①②③⑥D．②③④⑥