九年级第一学期物理书（如图）连同封面一共有66页，则物理书平放时对桌面的压强约为（　　）

发原题上来

答案为 B,点F所经过的路径为一段圆弧,该圆以AC为直径（两倍根号三）,经过原点O,圆弧所对应的圆心角为60度.所以=根号三乘以三分之π

已发~= =

小紫嫣=w=求分

ABABCABCCAABBCCABCBABBACA选择题.

没有试卷，能上传一份！

The young green consumer guide
This book says that our world is in danger.It is vital that we do something to save the earth.First of all,what are the threats to our environment?
The greenhouse effect
The writers ask us to "imagine the earth inside a kind of greenhouse with the atmosphere around it acting like the glass,letting sunlight in while keeping much of the warmth from getting out.The atmosphere is essential to all living things.Without it,the earth would be as cold and lifeless as the surface of the moon."
"The trouble is that our atmosphere is changing because we are polluting it with chemicals-in the form of gases-and it is keeping in too much heat!
These gases,mainly carbon dioxide(CO2),are produced by burning fuels such as petrol.The Greenhouse Effect may cause the level of the sea to rise and drown cities and even whole countries.
Damage to the ozone layer
The writers tell us that "ozone is a gas which occurs 20-50km above the ground.It forms an essential protective layer around the earth.Without it,the sun would burn us up."
We are making holes in the ozone layer mainly by using chemicals called CFCs.We use these in fridges and spray cans,and to make plastic items such as fast food boxes.
Destruction of the rain forests
The burning and cutting down of trees is making the Greenhouse Effect worse because trees take in CO2.It also causes erosion of the soil and flooding,as well as destroying the people and animals who make the frests their home.
Bad habits
Many of our habits cause pollution,especially our habit of using things once and then throwing them away.This creates massive mountains of rubbish.We do not know what to do with the rubbish and it pollutes our land and sea.For example,seven billion drink cans are thrown away in Britain each year.That is enough to reach from the earth to the moon.
How can we save the earth?
The book's idea is that we should become green consumers.That is,we should only buy and use things that do not damage the environment.And we should buy only from compaines that do not damage the environment either.
打得我手都酸了,就可怜一下吧.这篇课文我们刚刚学完,还不算太长,给你打了那么多,一定要用心看啊!

注：带＊号的为默写篇目,带▲号的为H版、S版的共有篇目
九年级（上）
*白雪歌送武判官归京
*小重山
*山坡洋•潼关怀古）
弈喻
干将莫邪
*池州翠微亭花
*渔家傲
*诏问山中何所有赋诗以答
*舟夜书所见
*黄鹤楼
*泊秦淮
*书湖阴先生壁
▲*论诗（各领风骚五百年）
*山园小梅