It's Saturday morning. My parents and I are on a tour bus. There are about twenty people on the bus. Some are from America, and some are from England and Australia. They are all our friends. We are going to the Great Wall. On the bus, there are two Chinese. One is a woman, the other is a man. The woman is good at English. She is talking with us about the Great Wall. The other people are listening to her. They like the Great Wall. They want to see it very much.

硫酸钾和硫酸铝的混合溶液，已知其中Al^3＋的浓度为0.4 mol/L，硫酸根离子浓度为0.7 mol/L，则K^＋的物质的量浓度为（）

阅读下列材料回答问题。
“知之为知之，不知为不知。”
“学而时习之，不亦说乎。”
“三人行，必有我师焉”。
---------请结合所学知识回答：

在杭州峰会的文艺演出中，传统戏曲与小提琴共鸣的《梁祝》、中国鼓与大提琴对话的《高山流水》、漫声讴歌的江南小曲《茉莉花》、世界经典的水上芭蕾舞《天鹅湖》……让我们真切感受到了中国神韵与世界文化的交融与对话。这表明（    ）

①不同文化在交流中相互融合相互渗透

②各国文化既有民族个性又有世界共性

③文化创新要广泛地引进和吸收外国文化

④不同文化交流和借鉴能够推动文化创新