题干

计算:3 48 ﹣9
1
3
+2 12
上一题 下一题 0.0难度 选择题 更新时间:2019-06-27 06:51:57

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解:原式=3×4 3 ﹣9× 33

同类题1

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》

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同类题5

阅读理解

    Driving in Canada is similar to driving in many parts of the United States. Distances and speeds, however, are posted in kilometers per hour and some signs, particularly in Quebec, may only be in French.

    Unless otherwise posted, the maximum (最大限度的) speed limit in Canada is 50km/hr in cities and 80km/hr on highways. On rural highways, the posted speed limit may be 100km/hr. It is illegal to take automobile radar detectors (汽车雷达检测器) into Quebec, Ontario, Manitoba, and the Yukon. Seat belt use is required by law for all passengers, and child car seats must be used by children under 40 pounds. Some provinces require drivers to keep their vehicles' headlights on during the day and some have banned (禁止) driving while using a hand-held cell phone. Motorcycles cannot share a lane (车道), and safety helmets for motorcycle riders and passengers are necessary. Running a red light is a serious crime throughout Canada and drivers are advised to stop before starting when a light turns green.

    Winter travel can be dangerous due to heavy snowfalls and icy conditions. Some roads and bridges are often closed in winter. Snow tires are required in some provinces. Travelers should also be careful about animals while driving at night in rural areas.

    Highway 401, from Detroit to Montreal, is one of the busiest highways in North America. It has been the scene of many deadly traffic accidents due to sudden and severe weather changes, high rates of speed, and heavy truck traffic. Thus drivers should be alert while travelling here.

    Please refer to our Road Safety page for more information. Also, we suggest that you visit the website of Canada's national authority responsible for road safety.