一、以理化生实验为话题的作文
一次天然课上，老师让我们做了一次奇特的小实验——纸片托水。
在天然课上，老师简单地讲了一下实验的技巧后，便让我们做起了实验。前面几许同学的实验做好了，便轮到了我。我走到讲台上，先打开水龙头，小心翼翼地在杯子里装满水，接着我拿起一张纸片，放在杯子上，假装使出了吃奶的劲儿，把纸片使劲的按了一下，接着把杯子快速的反转，你猜怎样着？那纸片竟然被杯子完全的吸住了，杯子里的水一滴都没有流出来，这让我疑惑不解，这纸片怎样就吸在了杯子上了呢？杯子里面的水这么就没流出来呢？真令我丈二和尚——摸不着头脑，我想：莫非是见鬼了？还是大气引力在帮助纸片呢？我带着满脑子的问号去问了天然老师。啊！原来这么神奇！原来啊，是大气压力在作怪，杯子里水的表面张力把纸片和杯子完全的闭合起来，因此杯子里水的压力小于杯子外大气压的压力，这样大气压就把纸片稳稳地托在杯子上了，杯子里的水天然不会流出来了。“原来是这样，这多么奇特啊！”我恍然大悟地说籂礌焚啡莳独锋扫福激道。我想：我以后一定要多做这样的实验，使我的课外智慧更加丰盛。
真可谓，大千全球，无奇不有，有许多的奥妙等待着我们去发现，去探索，去研究，这样才能使我们的学问越来越多。
二、英语作文：假设你是第三中学初一三班的班长，明天你们将在实验室（lab）里上天然科学课。请你根据老师的要
Attention please everyone,i have something important to tell you.
Tomorrow ,we will have our first Nature Science lesson.we should obey some rules.
First of all,remember to get to the lab on time.Don’t be late.we should leave a good impression on our Nature Science teacher.
Secondly,run after with each other is not allowed in the lab.
Thirdly,we mustn’t touch the things which is put on the desk without teacher’s permission.
What’s more ,put the things back to the place where it was be and wash your hands carefully.
Last but not least,it is important to make sure that the windows are closed and lights are not on.As we know,we should protect our environment from little things.
That’s all i want to say.Any questions.
打得好辛苦，希望采纳。本人初三，这篇应该有13分了
三、上天然科学课的缺点，英语作文
Nature has provided us with many kinds of resources. Almost everything we use in our everyday life comes from Nature. The food we eat, the water we drink, the clothes we wear, the concrete and bricks to build our houses, the materials to make bikes we ride, etc. , all come originally from Nature.
People have been making use of these natural supplies for thousands of years. With the development of technology and the increase of the population, the amount and range of materials taken has increased. It is estimated that this tread will continue in the years to come.
However, natural resouces are not in exhaustible. Some resources are already nearly used up. For example, the end of the world’s fuel is already within sight. Such an essential daily item as water is in short supply in many parts of the world.We can no longer thoughtlessly use the many resources provided by. Nature. We must learn to conserve what remains.
