46) This movement，driven by powerful and diverse motivations, built a nation out of a wilderness and, by its nature, shaped the character and destiny of an uncharted continent.

　　47)The United States is the product of two principal forces-the immigration of European people with their varied ideas, customs, and national characteristics and the impact of a new country which modified these traits.

　　48)But the force of geographic conditions peculiar to America, the interplay of the varied national groups upon one another, and the sheer difficulty of maintaining old-world ways in a raw, new continent caused significant changes.

　　49)The first shiploads of immigrants bound for the territory which is now the United States crossed the Atlantic more than a hundred years after the 15th- and -16th-century explorations of North American.

　　50)The virgin forest with its richness and variety of trees was a real treasure-house which extended from Maine all the way down to Georgia.

　　【題目解析】

　　46)本句重點(diǎn)詞語：driven by 在…的驅(qū)動(dòng)下，by its nature 從本質(zhì)上，它的性質(zhì)，

　　shape做動(dòng)詞當(dāng)"塑造"講。本句是一個(gè)由and連接的并列句，其中driven by powerful and diverse motivations,和by its nature為插入語結(jié)構(gòu)。

　　47)本句重點(diǎn)詞語：principle做形容詞，意為"主要的"， national characteristics 意為"民族特色，特點(diǎn)"，modify意為"修改，改變"。多次考察了of和with引導(dǎo)的后置定語的翻譯，前三小句為并列結(jié)構(gòu)表原因，第四小句為句子主干。

　　48)本句重點(diǎn)詞語：peculiar to，意為"特殊的，特有的"， national groups意為"民族"，固定搭配in a raw 意為"原始的"，sheer意為"完全的，純粹的"。

　　49)本句重點(diǎn)詞語：immigrant"移民"， explorations"探索"，bound for "駛往，開往"。其中，which is now the United States為定語從句修飾限定前文的the territory。

　　50)本句重點(diǎn)詞語：treasure-house"寶庫"，all the way down to "一直"，extend from…to…"從…延伸到…。其中with引導(dǎo)的介詞短語做后置定語，which extended from Maine all the way down to Georgia為定語從句修飾前面的treasure-house。

　　【參考譯文】

　　46)在多種強(qiáng)大的動(dòng)機(jī)驅(qū)動(dòng)下，這次運(yùn)動(dòng)在一片荒野上建起了一個(gè)國家，其本身塑造了一個(gè)未知大陸的性格和命運(yùn)。

　　47)美國是兩種主要力量的產(chǎn)物--即思想習(xí)俗、民族特色各異的歐洲移民和修改這些特征的新國家的影響的產(chǎn)物。

　　48)但由于美國特有的地理?xiàng)l件,不同民族的相互作用,以及維護(hù)原始老式方式的純粹困難,新大陸引起了重大變化。

　　49)在15-16世紀(jì)北美探索的一百多年之后，運(yùn)往該領(lǐng)土-即當(dāng)今的美國-的第一船移民橫渡了大西洋。

　　50)擁有豐富多樣樹種的原始森林是一個(gè)真正的寶庫，它從緬因州一直延伸到喬治亞州。