您正在看的高中三年级是:The USA。 ied from the earthquake. 一夜之间，唐山市被毁了，市内约有24万人死于地震。

　　2)短语动词 pass through 作"穿过"、"通过"、"路过"解，其中的 through可以 是介词，也可以是副词。例如：

　　He passed through the doorway and entered the room. 他穿过门口进入室内。

　　We're just passing through on our way to New York. 我们是去纽约的，只不过是路过这里。

　　They had to pass through the forest to get to the river. 他们必须穿过森林才能到达江边。

　　6，People who wanted to enter the USA had to go through a number of mental and physical tests and about 2 million people were turned away. 想要进入美国的人都必须经过多次的心理测验和体格检查，大约有200万人不准入境。

　　1)go through 作"经历(困难、痛苦等)"解(to suffer or eXPerience something bad)。例如：

　　His grandpa went through many dangers during the war. 在战争期间，他的祖父经历了许多危险。

　　She has gone through a lot since her husband was killed. 丈夫牺牲后，她经历了许许多多的困难。

　　They would go through fire and water to serve the people.为人民服务，他们情愿赴汤蹈火。

　　go through 还有许多其它的意思，最常见的是做"审阅"、"检查"、"翻找"解。例如：

　　Please go through these papers carefully.请你仔细审阅这些文章。

　　Mother went through the drawer looking for the sweater.母亲翻抽屉找那件毛线衫。

　　2) turn away作"拒不接纳"，"不准进入"解(to refuse to admit)。例如：

　　Because the hall was full,many people were turned away.因为大厅里已经满座，许多人被打发走了。

　　Crowds of people were turned away for lack of room.由于缺少场地，许多人被拒之门外。

　　7，A 55-storey building went up in 1913, and in 1931 the Empire State Building was completed, then the tallest building in the world. 1913年一座55层高的大楼拔地而起。 1931年帝国大厦竣工，这在当时是世界上最高的大厦。

　　then the tallest building in the world. 可以看作是下列非限制性定语从句的省略：…,(which was) then the tallest building in the world,其中的 which 代替主句中的主语 the Empire State Building,这个定语从句对这个主语作补充说明。又如：

　　He bought the car in 1980, then a modern type in China.

　　他于1980年买了这部汽车，当时在中国这还是一种新型的车子。

　　8，It is thought that they arrived more than 30,000 years ago by crossing a land bridge from Asia to America.他们被认为是在3万多年以前从亚洲跨越一座陆桥来到美洲的。

　　1)本句是由形式主语 it引导的句子，真正的主语是后面的　 that-clause。句中的　 It　 is thought that…大体相当于：People think that ….因此，本句可以改写成：

　　People think that they arrived more than 30,000 years ago by crossing a land bridge from Asia to America.

　　或者改写成：

　　They are thought to arrive more than 30,000 years ago by crossing a land bridge from Asia to America.

　　9，Now that they could ride horses, it became easier to hunt the bison,a type of cattle which used to exist in huge numbers on the plains of America. 既然土著人会骑马了，猎取野牛也就容易了。这种野牛以前是成群结队地生活在美洲平原上的。

　　这是一个复合句。主句是由形式主语 it引导的句子：it became easier to hunt the bison，随后跟着的 a type of cattle是 bison的同位语，并由定语从句 which used to … the plains of America 所修饰。 Now that they could ride horses 是表示原因的状语从句。

　　1)now that是一个连词词组，作"既然"(since)解，连接一个表示原因的状语从句。在口语中这个that常可省略，而只用now连接从句。而now在从句中已失去了"现在"的时间概念(从句中不一定要用现在时态)。不过，严格地说，now that多少含有"到这时"，"到达……的阶段或状态"的意思。本句中的 now that they could ride horses 就含有"既然到了他们可以骑马的时候"的意思。例如：

　　Now (that) you are well again, you can work with them. 既然你已经康复了，你就可以跟他们一起工作。

　　Now (that) we are alone, we can speak freely. 既然没有别人了，我们就可以无拘束地谈谈了。

　　Now that you have finished your work, you may go. 既然你的工作完成了，你就可以走了。

　　Now that he was really gone,I felt very sorry. 到他真的离开了的时候，我倒感到很抱歉了。

　　2)in huge numbers 作"大量地"解(huge=very large/big)。也可以说"in big/large/great numbers"。注意，这个词组中的 number 要用复数(numbers)。例如：

　　One afternoon I saw ants coming out in huge numbers. 有天下午我看到大批大批的蚂蚁出来了。

　　That day we killed and wounded the enemy in great numbers. 那天我们杀伤了大量的敌人。

　　Food supplies are coming in large numbers. 食品供应源源而来。

　　10，From 1830 onwards in the USA and from about 1870 in Canada, settlers began to move westwards and to take possession of the plains as their own. 美国自1830年起，加拿大从1870年左右起，殖民者开始向西迁移，并把平原据为已有。

　　1)from…(time) on/ onwards 从……(时候)起。如 from　 now　 on/onwards(从现在起)，from then on/onwards(从那时起)，from that night on/onwards(从那夜起)，from 1980 onwards(从1980年起)。例如：

　　From now on you're my students. 从现在起，你们就是我的学生了。

　　From that time onwards they began to pass through the forest. 从那时起他们就开始穿越森林。

　　From 1990　onwards the city began to take on a new look. 从1990年起，这个城市开始出现了新面貌。

　　后缀 -wards 常构成副词，表示"向"，如：eastwards(向东)， southwards(向南)，westwards(向西)， northwards(向北)， backwards(向后)， upwards(向上)， forwards (向前)，afterwards(以后)等。

　　2) take possession of夺取，占有。例如：

　　A