英语作文朋友遭遇龙卷风【一】
龙卷风必须在很强的积雨云下才可能出现，它的身体像一根园柱子，最上面的积雨云像一个帽子，它是一种急剧旋转的小而强烈的螺旋状风，很猛烈，足以把人、车，甚至建筑物突然抬起卷到空中。龙卷风快来临时，天空会出现一片绿色的像一块茂密的草地似的乌云，过了一会儿从云中间飞出一根旋转着的倒圆锥体，它的中部风速很强，足以把任何东西卷上天空。它能毁坏许多房屋，把大树连根拔起，造成许多灾难。
自然界有许多对人类有害的自然现象都被人类利用起来了。我相信，有一天龙卷风也能造福人类。
英语作文朋友遭遇龙卷风【二】
龙卷风长期以来一直是个谜，正是因为这个理由，所以有必要去了解它。龙卷风的袭击突然而猛烈，产生的风是地面最强的。由于它的出现和分散都十分突然，所以很难对它进行有效的观测。
什么是龙卷风
龙卷风是一种涡旋：空气绕龙卷的轴快速旋，受龙卷中心气压极度减小的吸引，近地面几十米厚的一薄层空气内，气流被从四面八方吸入涡旋的底部。并随即变为绕轴心向上的涡流，龙卷中的风总是气旋性的，其中心的气压可以比周围气压低百分之十。
龙卷风的形成
龙卷风是云层中雷暴的产物。具体的说，龙卷风就是雷暴巨大能量中的一小部分在很小的区域内集中释放的一种形式。龙卷风的'形成可以分为四个阶段：
（1）大气的不稳定性产生强烈的上升气流，由于急流中的最大过境气流的影响，它被进一步加强。
（2）由于与在垂直方向上速度和方向均有切变的风相互作用，上升气流在对流层的中部开始旋，形成中尺度气旋。
（3）随着中尺度气旋向地面发展和向上伸展，它本身变细并增强。同时，一个小面积的增强辅合，即初生的龙卷在气旋内部形成，产生气旋的同样过程，形成龙卷核心。
（4）龙卷核心中的旋与气旋中的不同，它的强度足以使龙卷一直伸展到地面。当发展的涡旋到达地面高度时，地面气压急剧下降，地面风速急剧上升，形成龙卷。
龙卷风的探测
龙卷风的风速究竟有多大？没有人真正知道，因为龙卷风发生至消散的时间短，作用面积很小，以至于现有的探测仪器没有足够的灵敏度来对龙卷风进行准确的观测。相对来说，多普勒雷达是比较有效和常用的一种观测仪器。多普勒雷达对准龙卷风发出的微波束，微波信号被龙卷风中的碎屑和雨点反射后重被雷达接收。如果龙卷风远离雷达而去，反射回的微波信号频率将向低频方向移动；反之，如果龙卷风越来越接近雷达，则反射回的信号将向高频方向移动。这种现象被称为多普勒频移。接收到信号后，雷达操作人员就可以通过分析频移数据，计算出龙卷风的速度和移动方向。
龙卷风的危害
1995年在美国俄克拉何马州阿得莫尔市发生的一场陆龙卷,诸如屋顶之类的重物被吹出几十英里之远。大多数碎片落在陆龙卷通道的左侧，按重量不等常常有很明确的降落地带。较轻的碎片可能会飞到300多千米外才落地。
龙卷的袭击突然而猛烈，产生的风是地面上最强的。在美国，龙卷风每年造成的死亡人数仅次于雷电。它对建筑的破坏也相当严重，经常是毁灭性的。
在强烈龙卷风的袭击下，房子屋顶会像滑翔翼般飞起来。一旦屋顶被卷走后，房子的其他部分也会跟着崩解。因此，建筑房屋时，如果能加强房顶的稳固性，将有助于防止龙卷风过境时造成巨大损失。
英语作文朋友遭遇龙卷风【三】
Zeng Qiao is one of my friends. She is a beautiful, outgoingand good-tempered girl. She smiles frequently. I think it’s her smile that makes her beauty. We live in the same dormitory, so that we always stay together, no matter going to classroom or having dinners. At first, I don’t like her very much, because she is always talking. It seems that she can’t stop open her mouth. I am a little bit quiet and introverted, so I seldom talk to others. But gradually, I find that she can have influence on others by what she says. Zeng Qiao likes sharing interesting things with others. For example, she likes telling us her funny stories of her childhood or her former classmates. She always tells me that I should be more extroverted and learn to talk to others. Under the influence of her, I communicate with others more frequently and I find that it feels so great. I am so grateful that I can have such a good friend.
曾巧是我的一个朋友，她是个漂亮活泼，脾气又好的女孩子。她很喜欢笑，我觉得是她的笑容使她看上去漂亮。我们住同一间宿舍，因此不管是去教室还是吃饭都形影不离。之前我并不喜欢她，我认为她太喜欢说话了，总是停不住她的嘴。相反我性格内向，喜欢安静，很少跟别人说话。但是渐渐地，我发现她是个善于用言语影响别人的女孩子，她喜欢跟别人分享有趣的事，那些童年的故事或是以前同学的事情。她经常开导我要变得外向，多试着跟别人说话。在她的.影响下，我跟别人交流也更多了，并且发现这感觉非常好。我觉得有这样的朋友很幸运!
英语作文朋友遭遇龙卷风【四】
I have a lot of friends in Simon English School. One of them is my best friend. His name is boyd.
He and I are both thirteen years old. but I am older than he, and I am fatter than he too. He is shorter than I, and he is thinner than I. He wears a pair of glasses but I don't.
He likes to eat pocket-food, and he is a gentleman in a sense that when he has pock-food he will share them with us.
He and I are in the same school and in the same class. So, we can help each other. We alway play in the school together. he likes to do thing I like. He lives in the Ningbo Jiangdong, so he hardly came to my home in Zhenghai but I alway go to his home on weekends and he sometimes will come to my home on weekends. Sometimes we will fight but we alway get along well.
His mother is a doctor in the Li-Hui-Li hospital and I know where her office is. His father is a worker in the Bei-Lun power plant. He is a head of a group. So, his father has a lot of work to do.
He and I are in the same school. We usually have a good time so he is my best friend.
英语作文朋友遭遇龙卷风【五】
How was your day off?Did you have fun playing volleyball?Iwas very happy in my day off.I went to the movie with my friends.That movie was interesting,and I went to my cousin's home.I played computer game with him.It was so great .I went to the gift shop and saw many nice gifts.Of course.I bought a gift for my friend. It was a really nice gift.Oh,that day was so great!See you soon!
Love,
Jack
英语作文朋友遭遇龙卷风【六】
My name is Wu Yuwei .I’m 13 years old. I’m a Chinese girl .I study in Xinqi PrimarySchool.I’m in Class 3,Grade 6. I’m in Row 3. I have many friends in class.For example, Che Lei is my best friend . She is 13 years old , too. She is a good girl. We often help each other.There are four people in my family .They are my father, mother, sister and me .My parents are formers . They work hard. My sister is a student . I love them and they love me ,too.
