点击切换搜索课件文库搜索结果(9701)
文档格式:PPT 文档大小:184KB 文档页数:30
一、领土构成、自然环境和资源 1、自然环境 1.地理位置:美国西临太平洋,东临大西洋,远离旧大陆,其南北两面都同弱国相邻。 2.地形 (1)西部的高原山地:由科迪勒拉山系组成,东西两侧分别为落基山脉和太平洋沿岸山脉,其间为宽阔的哥伦比亚高原、大盆地和科罗拉多高原
文档格式:PPT 文档大小:977KB 文档页数:118
直流电机由静止的部分定子和旋转的部分 转子两大部分构成: 1、定子部分:定子包括机座、主磁极、换向 极和电刷装置等。 1)主磁极:在大多数直流电机中,主磁极是 电磁铁,为了尽可能的减小涡流和磁滞损 耗,主磁极铁心用1~1.2mm厚的低碳钢 板叠压而成。整个磁极用螺钉固定在机座 上
文档格式:DOC 文档大小:54.5KB 文档页数:17
2002年1月全国大学英语四级考试真题和答案 Part I Listening Comprehension(20 minutes) Section a Directions: In this section, you will hear 10 short conversations. At the end of each conversation, a question will be asked about what was said. Both the conversation and the question will be spoken only
文档格式:DOC 文档大小:47KB 文档页数:14
2001年6月全国大学英语四级考试真题和答案 Part I Listening Comprehension(20 minutes) Section a Directions: In this section, you will hear 10 short conversations. At the end of each conversation, a question will be asked about what was said. Both the conversation and the question will be spoken only once. After each question there will be a pause. During the pause, you must read the four choices
文档格式:DOC 文档大小:47KB 文档页数:14
2001年1月全国大学英语四级考试真题和答案 Part I Listening Comprehension(20 minutes) Section a Directions: In this section, you will hear 10 short conversations. At the end of each conversation, a question will be asked about what was said. Both the conversation and the question will be spoken only once. After each question there will be a pause. During the pause, you must read the four choices
文档格式:DOC 文档大小:47KB 文档页数:14
2000年6月全国大学英语四级考试真题和答案 Part I Listening Comprehension(20 minutes) Section a Directions: In this section, you will hear 10 short conversations. At the end of each conversation a question will be asked about what was said. Both the conversation and the question will be spoken only once. After each question
文档格式:DOC 文档大小:55KB 文档页数:12
2008年12月全国大学英语四级考试真题和答案 Part I Writing(30minutes) 注意:此部分试题在答题卡1上。 Part II Reading Comprehension( Skimming and Scanning(15 minutes) Directions: In this part, you will have 15 minutes to go over the passage quickly and answer the questions on Answer Sheet 1. For
文档格式:DOC 文档大小:72.5KB 文档页数:11
2008年6月全国大学英语四级考试真题和答案 写作部分(9:009:30) Part I Writing(30 minutes) Directions: For this part, you are allowed 30 minutes to write a Letter of Apology according to th utline given below. You should write at least 120 words following the outline given below in Chinese
文档格式:DOC 文档大小:83.5KB 文档页数:15
2007年12月全国大学英语四级考试真题和答案 Part I Writing(30 minutes) 注意:此部分试题在答题卡1上 Part II Reading Comprehension( Skimming and Scanning)(15 minutes) Directions: In this part, you will have 15 minutes to go over the passage quickly and answer th uestions on Answer Sheet 1. For questions 1-7, choose the best answer from the four choices marked
文档格式:DOC 文档大小:54.5KB 文档页数:13
2007年6月全国大学英语四级考试真题和答案 Part I Writing(30 minutes) 注意:此部分试题在答题卡1上 Directions: For this part, you are allowed 30 minutes to write a short essay on the topic of Welcome to our club. You should write at least 120 words following the outline given bellow: 欢迎辞,欢迎加入俱乐部。 标题: Welcome to our club
首页上页955956957958959960961962下页末页
热门关键字
搜索一下,找到相关课件或文库资源 9701 个  
©2008-现在 cucdc.com 高等教育资讯网 版权所有