If you want to study abroad, have you thought about where to live? I've been living and studying in Canada for about nine months. As I'm still too young to rent an apartment by myself. I live with a homestay family and I feel like I'm part of it.

    The first time I had a homestay was in 2013. During that time, I stayed in Ajax, a town in Canada, for a week and lived with a homestay family. Carlton lives with his nephew and his niece-in-law. Carlton drove me to an international school to learn about Canadian culture every morning, and he picked me up in the afternoons. Our leisure time was in the evening. The meals he made for me were delicious and we usually watched a movie after dinner. All experiences left an unforgettable impression on me, even if I didn't live there for a long time.

    I'm now living with a Hungarian(匈牙利) family with another Chinese boy. There are two family members--- Mrs Perger and her son, Robert. I've already lived here for nine months and I have been deeply moved by many things they've done. Once, my roommate went running and didn't come back for quite a long time. Mrs Perger called him, but he didn't answer the phone. She began to worry about him, and was even about to cry.

    However, living with a homestay family also has its disadvantages, especially when living with a foreign family. The biggest challenge for me has been the totally different lifestyle, which took me a long time to get used to.

    Living with a homestay family has given me a lot of new experiences. It has taught me how to communicate with different people. Moreover, when different lifestyles and cultures meet together, I have seen that the spark(火花) they make are spectacular(壮观的).

世界历史是一部大国崛起和衰落交替的历史，大国关系是当今世界关系的主角，大国之间的较量一定程度上影响着历史发展的进程。请阅读材料回答问题：

材料一：近500年来发生过三次结构性的权力转变……第一次是西方世界（欧洲）的崛起，此转变始于15世纪，在19世纪急剧加速；第二次转变发生在19世纪末美国的崛起……第三次是最近二十年开始的美国之外的世界崛起。

──（美）法里德•扎卡里亚《后美国世界》

材料二：（美国）仅1865年至1900年，被正式批准登记的发明专利就达到了64万多种……为促进科学和实用技艺的普及，对作家和发明家的著作和发明，在一定期限内给予专利权的保障……美国人第一次把专利权写入了宪法，用国家的根本大法来保护发明创造。

材料三：英国工业界满足于第一次工业革命的成就，坐享其成的思想日趋严重……在新技术成果应用方面英国日趋落后。政府在科技投入方面也存在诸多问题：经费少，实验设备不足，管理混乱，科技人员地位低和待遇差成为普遍现象。

──《世界通史》

材料四：所有的大国都试图建立符合自己利益的世界秩序，所以他们总是为世界秩序出谋划策。实际上，那些正在崛起的国家想要打破这种秩序，因为他们试图取代以前的大国。

──《大国崛起》

材料五：作为全球最大的发展中国家和仅次于美国的第二大经济体，中国已然成为具有系统重要性的全球经济力量。调速增效成为中国经济打造可持续增长“新常态”的关键所在。……中国经济的“新常态”既是全球“新局势”的重要组成，又深刻地改变着中国和世界的关系。……在“新常态”之下，中国经济和全球经济的互动方式正在重构，全球经济再平衡进程提速。……从金砖银行到亚投行和丝路基金，从大力推动“一带一路”建设到推进贸易便利化，中国正不断增强与世界经济的“粘合力”。

──摘自人民网《从全球经济新局势看中国经济新常态》

请回答：

中共历史上有许多具有转折意义的会议，其中被称为党的历史上和中国革命史上生死攸关转折点的是（    ）

星期天，我们要去西安市历史博物馆参观，不知如何乘车，应选择