【机遇与挑战并存】

材料一：1853年一直想打通“朝向欧洲窗户”的俄国，为争夺巴尔干半岛的控制权而和英法等国爆发了克里米亚战争，战争以俄国的失败而告终。战争中双方的力量对比如下：克里米亚战争双方实力对比表

材料二：1853年，一支美国舰队闯入日本港口，要求谈判通商，否则立即向日本开战。第二年，日本被迫在不平等条约上签字，同意开放港口。

有一条酸河，经分析发现是由于河水中含有的物质R在氧气的作用下发生反应所致，其反应的化学方程式为2R＋2H₂O＋7O₂＝2FeSO₄＋2H₂SO₄，则R的化学式是

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    There were many famous explorers during 1400--1600. What were the names of the most famous explorers? What were the major achievements of the famous explorers? This website provides what you want to know.

    Famous Canadian Explorers   The discovery of the New World opened up new colonies(殖民地) in Canada. One of the most famous Canadian explorers was Louis Joliet who explored the Great Lakes area and discovered the Mississippi River.

Famous Spanish Explorers Famous Spanish explorers explored the Caribbean and South America. Just a few famous Spanish explorers conquered (征服) millions of local people who made up the nations of the Incas and the Aztecs. Famous Spanish explorers included Hernando Cortes, Francisco Pizarro, Hernando De Soto, Vasco Nunez de Balboa and Juan Ponce de Leon.

Famous English Explorers The most famous English explorers started their voyages of discoveries during the Elizabethan reign of Queen Elizabeth I. The most famous English explorers included Sir Walter Raleigh, Sir Francis Drake, Sir Martin Frobisher and Sir John Hawkins.

    Famous Portuguese (葡萄牙的) Explorers   The famous Portuguese explorers led the way when it came to exploration. The most famous Portuguese explorers included Ferdinand Magellan, Vasco da Gama, Bartholomeu Dias and Miguel Corte-Real.

把右边5个 圈起来。