求一篇用英语写的有关UFO的文章
题目
求一篇用英语写的有关UFO的文章
200字左右.
答案
A UFO or Unidentified Flying Object is any real or apparent flying object which cannot be identified by the observer and which remains unidentified after investigation.
Sightings of unusual aerial phenomena date back to ancient times,but reports of UFO sightings started becoming more common after the first widely publicized U.S.sighting in 1947.Many tens of thousands of such claimed observations have since been reported worldwide,and it is very likely many more go unreported due to fear of public ridicule because of the Social stigma created around the UFO topic.
In popular culture throughout the world,UFO is commonly used to refer to any hypothetical alien spacecraft but the term flying saucer is also regularly used.Once a UFO is identified as a known object (for example an aircraft or weather balloon),it ceases to be a UFO and becomes an identified object.In such cases it is inaccurate to continue to use the acronym UFO to describe the object.
举一反三
已知函数f(x)=x,g(x)=alnx,a∈R.若曲线y=f(x)与曲线y=g(x)相交,且在交点处有相同的切线,求a的值和该切线方程.
我想写一篇关于奥巴马的演讲的文章,写哪一篇好呢?为什么好
最新试题
热门考点
- DO ---- know Ms.Wang? A.your friend B.your friends C.he friend D.he friends
- 《给家乡孩子的信》后面练习题 怎么做.知道什么意思吗? 求助
- 甲,乙两人练习骑自行车,已知甲每小时比乙多行驶6千米,甲骑90千米所用的时间和乙骑60千米所用的时间相等求甲,乙每小时各行驶多少千米?
- 小明和爸爸今年的年龄和是36岁,再过 10年,小明的年龄是爸爸的40%,小明和爸爸 今年的年龄各多少
- 54km/h=()=()m/s(中间写过程)
- 已知正方形ABCD,E在BD上,EM⊥BC,EN⊥CD,求证 MN=AE
- 有关团结合作的谚语词语
- This pair of jeans __ long for me to wear .Here is a shorter one.Please try it on.
- 已知二次函数y=x2-(m-2)x+m+3.根据下列条件求m的值:
- 7小时39分等于几小时.(填小数)