谁能用英语介绍一下美国 50字左右 （急用）

The United States in the North Central and North America also includes the territory of Alaska and the Pacific northwest of the Hawaiian Islands in Central. North and the Canadian border, south through the Gulf of Mexico, west Pacific, East Bin Atlantic. Coastline of 22,680 kilometers. Most areas of continental climate, the southern subtropical climate. Big temperature difference between north-central plains, Chicago January average temperature -3 ℃, 7月24 ℃; Gulf Coast in January the average temperature of 11 ℃, 7月28 ℃.
Climate
The United States has almost all the world's climate types, in the main agricultural zone in rare severe drought, flooding is not uncommon, and a moderate while the temperature to adequate rainfall.
Climate impact on the United States is the main Arctic air, from the Pacific each year bring a large-scale low pressure, these low pressure through the Nevada mountains, the Rocky Mountains and the Cascade range, attach a great deal of moisture, when they arrived at the central pressure Great Plains, will be able to reorganize, leading to the main air masses meet and bring a fierce thunderstorm, especially in the spring and summer. These may sometimes heavy rain and low pressure to join the other, continue to the East Coast and the Atlantic Ocean, and will become more intense storms in the northeast (Nor'easter), in the United States in the Northeast Atlantic region and New England a wide-ranging and heavy snowfall. Great Plains incomparably vast grassland has also developed a number of the world's most extreme climate change phenomenon.
美国位于北美洲中部,领土还包括北美洲西北部的阿拉斯加和太平洋中部的夏威夷群岛.北与加拿大接壤,南靠墨西哥湾,西临太平洋,东濒大西洋.海岸线22680公里.大部分地区属于大陆性气候,南部属亚热带气候.中北部平原温差很大,芝加哥1月平均气温－3℃,7月24℃；墨西哥湾沿岸1月平均气温11℃,7月28℃.
气候
美国几乎有着世界上所有的气候类型,在主要农业地带少有严重的干旱发生、洪水泛滥也并不常见,并且有着温和而又能取得足够降雨量的气温.
影响美国气候的主要是北极气流,每年从太平洋带来了大规模的低气压,这些低气压在通过内华达山脉、洛矶山脉、和喀斯喀特山脉时夹带了大量水分,当这些气压到达中部大平原时便能进行重组,导致主要的气团相遇而带来激烈的大雷雨,尤其是在春季和夏季.有时这些暴雨可能与其他的低气压会合,继续前往东海岸和大西洋,并会演变为更激烈的东北风暴（Nor'easter）,在美国东北的中大西洋区域和新英格兰形成广泛而沉重的降雪.大平原广阔无比的草原也形成了许多世界上最极端的气候转变现象.