在日常生活或是工作学习中，说到作文，大家肯定都不陌生吧，借助作文人们可以实现文化交流的目的。写起作文来就毫无头绪？
八年级上册英语作文 1
Li Xiaohu spent too much time playing computer games and he fell behind others. As a good/close friend of his, I must do something to help him.
First, I think its very important for him to learn lessons well. He should spend most of his time on his study instead of computer games.
Secondly, I must tell him that playing computer games too much is bad for his health, especially for his eyes. So he must give it up. I can play more sports with him after school. Maybe he will become more interested in sports than computer games. And then Ill ask him to concentrate more on his study. Of course, I will try my best to help him with all his subjects. I think I can do it in many fun ways and let him find much fun in studying. At the same time, Ill ask both his parents and our teachers to help him, too. If I try these, Im sure he will make great progress soon.
八年级上册英语作文 2
Today, I am telling you about my hometown.
In the east of China, there is a small city---Haimen. I was born there. Haimen is not far from Shanghai. It’s at the mouth of the Changjiang River.
Haimen is a modern city. There are lots of high buildings in it. In the center of Haimen, there are many shops. You can buy some nice things here. Things in most shops aren’t expensive. You can pay a little money and they are yours.
My hometown is a beautiful city. On each of the roads, there are some big trees and nice flowers. The roads are also very clean. They make people happy and comfortable.
The seasons here are very nice. I like autumn best. The weather is neither hot nor cold. A poem says “Flyer of summer come to my window to sing, then fly away. And yellow leaves of autumn, which have no songs, just fall there with a sign.” It’s very cool.
I love Haimen. It’s a nice place to live. Welcome to my hometown
八年级上册优秀英语作文 3
Li Xiaohu spent too much time playing computer games and he fell behind others. As a good/close friend of his, I must do something to help him.
First, I think it's very important for him to learn lessons well. He should spend most of his time on his study instead of computer games.
Secondly, I must tell him that playing computer games too much is bad for his health, especially for his eyes. So he must give it up. I can play more sports with him after school. Maybe he will become more interested in sports than computer games. And then I'll ask him to concentrate more on his study. Of course, I will try my best to help him with all his subjects. I think I can do it in many fun ways and let him find much fun in studying. At the same time, I'll ask both his parents and our teachers to help him, too. If I try these, I'm sure he will make great progress soon.(约165字)
八年级上册英语作文 4
Dear Friend Thank You For your Love
Dear friend Lucy, thank you for your love. We get on well with each other in day-to-day lives. As for my friend, you always help me with my study. When I have a few
difficulties, you always encourage me to get over difficulties.
Do you remember? Last semester, I forgot to do my homework. So the next day, I wanted to copy your homework. Because I really didn’t want to be criticized. But you
said you couldn’t lend your homework to me, it was very bad solution. Even if I said I would never do it except this time. Please lent me your homework. But you still
said maybe it would start a bad habit. I should do my own homework. So I was pretty angry. I said I wouldn’t become your friend anymore. A few days later, I thought I
was sorry. So I told you to forgot this thing. I wanted to make friends with you. And I was happy you said OK.
Now I ‘m certain you are my best friend. Dear friend Lucy, thank you for your love.
八年级上册英语优秀作文相关文章：
8年级上册英语作文简单的作文 5
Mother's day is coming. I want to give mom a gift. What can I do for you? My mother needs both work and housework. And take care of me, with wrinkles on my face and hands, and buy my mother a bottle of lotion or a hand cream to keep my mother young. But the shops and the hand cream are expensive. I don't have enough money. If you want to think about it, don't buy your mother a wish bottle. I went to the store to buy a purple wish .com bottle for my mother, and I spent a dozen dollars on it. But I think is not enough, so he thought for a long time thinking of home can give mom a card, but I think of my mother every time card mother seems to be not very fond of. Suddenly I had an idea to write a calligraphy work for my mother, so I wrote a calligraphy piece.
Mother's day arrived, I put the bottles and vows that shu-fa zhang works together to mother, mother looked at the face a hearty laugh, said: ”baby, this is the best gift you give mom.“
8年级上册物理课件 6
8年级上册物理课件
●教学目标
一、知识与能力
1.了解眼睛的构造，知道眼睛是怎样看见物体的。
2.了解眼镜是怎样矫正视力的。
二、过程与方法
1.通过观察实验和实践，培养学生理论联系实际，实事求是，求真务实的科学态度。
2.培养学生的观察能力、思维能力、参与组织能力和实践能力。
三、情感态度与价值观
1.通过活动，培养学生珍惜生命，关爱健康的意识，使其能自觉注意保护视力。
2.通过活动，培养学生将科学技术应用于日常生活的意识。
●教学重点新 课 标 第 一 网
培养学生用前面所学凸透镜成像规律的知识，加深对眼睛的了解。
●教学难点
将科学知识应用于日常生活的意识的培养。
●教学方法
观察法、讨论法。
●教学用具
挂图、眼睛模型、投影仪、球、书、石块、冰块、盐水杯。
●课时安排
1课时
●教学过程
一、创设情境、引入新课
[师]同学们闭上眼睛，用手摸这些东西(球、书、石块、冰块、盐水杯等)，每摸一样，说出这是什么？
教师在教室里走动，拿着不同东西，让学生们摸。
[师]为什么不用眼睛，用手摸也能知道某一物体的形状、大小、凉热等特点？
[生]因为我们有触觉、味觉、视觉、嗅觉、听觉，能摸出来是触觉的作用。
[师]这位同学说得很对，其实这些东西的特点，除了用手摸，用眼睛一下就看出来了。眼睛是一个既复杂又奇妙的器官，它帮助我们认识身外的世界。判断物体的大小、距离、质感、颜色及长、宽等。你们知道眼睛是如何看到物体的吗？上节课我布置收集关于眼睛的资料，来说给大家听。
二、新课教学
[放投影片，课本图3.4-1，眼球的结构，让同学们通过挂图和投影片讲叙]
[生甲]眼睛的主要部分是眼球，眼球近似球体。此外，还有一些附属结构。
[生乙]眼球由角膜、晶状体、瞳孔、虹膜、睫状体、玻璃体、视网膜等组成。
[生丙]晶状体和角膜的共同作用相当于一个凸透镜。
[生丁]外界物体反射来的光线，经过角膜、房水，由瞳孔进入眼球内部，再经过晶状体、玻璃体的折射作用，会聚在视网膜上，形成物体的像。
[生戊]视网膜上的视神经细胞受到光的刺激，把这个信号传输给大脑，我们就看到了物体。
[师]大家鼓掌，对他们精彩的讲解进行鼓励，谁还有不明的问题，请提出来。
[生甲]眼睛的睫毛、眼皮不属于眼球的构造，属于什么？
[生乙]眼睛睫状体起什么作用？
[生丙]眼睛中瞳孔起什么作用？
[生丁]视网膜起什么作用？
[生戊]既然晶状体和角膜的共同作用相当于一个凸透镜，那么物体能成什么样的像？
[师]请从你们收集到的资料中来解决这些问题。
[生甲]眼球的附属结构：有使眼球运动的肌肉，保护眼球的眼睑、睫毛、结膜、泪器。
[生乙]眼睛的睫状体的作用是调节晶状体的形状，当睫状体放松时，晶状体比较薄，远处物体射来的光刚好会聚在视网膜上，眼球可以看清远处的物体；当睫状体收缩时，晶状体变厚，对光的偏折能力变大，远处物体射来的光会聚在视网膜上，眼睛就可以看清近处的物体。
[生丙]眼睛瞳孔的作用能改变大小以控制进入眼睛的光线量，若在一个阳光普照的室外环境下，由于我们的眼睛不用太多光线来观看物体。瞳孔会自动收缩；相反，在漆黑的环境下，由于我们需要更多的光线来看物体，瞳孔便会自动扩张，瞳孔好像照相机的光圈。
[生丁]眼睛中视网膜的作用是把物体成的像的光能转变为神经冲动，再经过通往大脑的神经把神经冲动传入中枢神经系统，到达大脑皮层的视觉中枢，产生视觉，视网膜好像照相机的底片。
[生戊]光线由物体射入眼球，经过角膜和晶状体(相当于凸透镜)的折射，然后到达视网膜形成倒像，但我们看见的物体都是直立的物像，是因为受生活经验的影响。
[师]大家回答的非常好，说明在课下做了不少工作，说明准备得很充分，我们的眼睛就是这样：光线由我们所观看的物体发出，经过瞳孔(好像照相机的光圈)再由角膜及晶状体(功能好像照相机的镜头)，再会聚在视网膜上(好像照相机的底片).
(一)眼睛(板书)
主要构造：
我们的眼睛实在了不起，我们不需要像摄影师那样，要考虑到环境的光暗或物体距离，我们的眼睛会自动作出调节，只要眼睛各部分运作正常，每一次我们均可“摄”取一张美丽动人的“相片”。
有些人单靠自身眼睛的调节已不能使像成在视网膜上，这种情况是怎么形成的，如何 处理？
[生甲]近视眼只能看清近处的物体，看不清远处的物体。
[生乙]远视眼只能看清远处的物体，看不清近处的物体。
[生丙]近视眼的视网膜距晶状体过远或者晶状体太凸，折光能力太强，致使远处射来的平行光线还未到达视网膜就已聚成一点，而当光线到达视网膜时又都分散开，形成一个模糊的光斑，因此看不清远处的物体。
[生丁]远视眼是视网膜距晶状体过近或者晶状体太扁，折光能力太弱，致使近处射来的平行光线到达视网膜时，还没有聚成一点，形成的物像落在视网膜的后方，在视网膜上形成一个模糊的光斑，因此，看不清近处的物体。
[师]那么怎么矫正近视眼和远视眼，看投影。(课本图3.4-3、图3.4-4)
[生甲]远视眼镜是凸透镜，是利用凸透镜能使光线会聚的特点，在眼睛前放一个凸透镜，就能使来自近处物体的光会聚在视网膜上。
[生乙]近视眼镜是凹透镜，使入射的平行光线经过凹透镜发散后再射入眼睛。
[师]同学们回答的非常好，还有什么问题？请继续提问。
[生甲]近视眼是怎么形成的？
[生乙]老花眼是怎么形成的？
[生丙]怎么预防近视眼？
[生丁]眼镜的度数是怎么来的？
[生戊]什么是假性近视？什么是真性近视？
[师]请同学们根据搜集的资料，找出答案。
[生甲]形成近视眼的原因，一般认为主要有两个方面，一是遗传因素，二是环境因素。其中环境因素是形成学生近视眼的主要因素。
[生乙]儿童、青少年眼睛中的晶状体弹性强，睫状体的调节能力大，但是如果看书写字的姿势不正确，书本放得离眼太近，或采光、照明条件不好，或持续用眼的时间过长，都会使睫状体内的肌肉持续收缩。晶状体凸度增大，久而久之，一旦看远方物体时，睫状体内的肌肉就不能放松。变凸的晶状体也不能恢复到正常状态，这样就造成了假性近视。
[生丁]发生假性近视以后，如仍不注意采取有效的防治措施，就会造成变凸的晶状体不能恢复正常，就会变成真性近视。
[生戊]预防近视要做到：①读书、写字姿势要正确，眼与书的距离约33 cm.②看书一小时后休息，要远眺几分钟。③要认真做眼睛保健操。④不要在直射强光下看书。⑤不在光暗的地方看书。⑥不躺卧着看书。⑦不在走路时看书。
[生己]老花眼产生的原因是由于老年人的晶状体弹性变差，调节能力减弱的缘故。是生理性变化引起的，看远物不需要晶状体的调节，但在看近物时，需要配戴凸透镜。
[生庚]透镜焦距f的长短标志着折光本领的大小。焦距越短，折光本领越大，通常把透镜焦距的倒数叫做透镜焦度。用Φ表示。
如果远视很严重，所戴花镜(凸透镜)的折光本领应该大一些，透镜焦度就要大一些，平时说的眼镜片的度数，就是镜片的透镜焦度乘100的值。例如：100度远视镜片的透镜焦度是1 m-1，它的焦距是1 m.
凸透镜(远视镜片)的度数是正数，凹透镜(近视镜片)的度数是负数。
[师]现在我们知道了近视眼是怎么形成的了，但如何预防？如何矫正？
(二)近视眼及其矫正。
近视眼的视网膜距晶状体过远，从无穷远处射来的平行光线会聚在视网膜前，用凹透镜矫正。
(三)远视眼及其矫正。
远视眼的视网膜距晶状体过近，平行光的会聚点在视网膜后，用凸透镜矫正。
三、小结
1.眼睛好像一架照相机，主要由瞳孔(好像照相机的光圈)、角膜及晶体(功能好像照相机的镜头)、视网膜(好像照相机的底片)组成。
2.近视眼用凹透镜矫正。
3.远视眼用凸透镜矫正。
四、布置作业
P64动手动脑学物理①②③.
P65科学世界①②.
[动手动脑学物理习题参考答案]
1.甲图平行光线通过凸透镜后，会聚于焦点，是正确的。
过焦点的光通过凸透镜后应成为平行光，而乙图的光线向外发散，是错误的。
光线通过凹透镜后应发散，而丙图的光线通过凹透镜后向主光轴
