在编制预算的过程中，企业管理者大体上估计出涉及的众多变量发生变化的可能性，近似地判断

为研究水滑石的组成、结构和性质，某校研究性学习小组取得了二种牌号的水滑石样品拟进行探究，请你参与探究并回答相关问题。

（1）甲同学取天然水滑石样品进行恒重分析，已知天然水滑石的化学式可表示为：6MgO·Al₂O₃·CO₂·12H₂O，取0.1mol水滑石进行加热时，温度与剩余固体质量的关系如下图,平行线上的数字表示残留固体的质量。

当温度在0～280℃质量不变，是什么原因：         。

A→B减少的物质及其物质的量为：          ；

C→D减少的物质及其物质的量为：               ；

D处化学组成为：                              。

（2）乙组取的CA（美国化学文摘）登记号为12304-65-3　的合成水滑石样品，现只知其化学式为：Mg_aAl_b(OH)_C(CO₃)_d， a+b+c+d="25," a、b、c、d为正整数。取该水滑石样品0.1mol,用1mol/L盐酸使其完全溶解。

①消耗盐酸的体积至少为：              　　　L（用字母表示）；

②若参加反应的盐酸的物质的量与生成CO₂的物质的量之比为18∶1，则该水滑石的化学式为：     　　　            。

EAN。UCC条码标识系统及其应用领域

阅读理解

    The word "conservation" has a thrifty (节俭) meaning.To conserve is to save and protect, to leave

what we ourselves enjoy in such good condition so that others may also share the enjoyment.Our

forefathers had no idea that human population would increase faster than the supplies of raw materials;

most of them, even until very recently, had this foolish idea that the treasures were "limitless" and

"inexhaustible".  Most of the citizens or earlier generations knew little or nothing about the complicated

and delicate system that runs all through nature, and which means that, as in a living body, an unhealthy

condition of one part will sooner or later be harmful to all the others.

     Fifty years ago nature study was not part of the school work; scientific forestry (林地) was a new

idea: timber (木材) was still cheap because it could be brought in any quantity from distant woodlands;

soil destruction and river floods were not national problems; nobody had yet studied longterm climatic

cycles in relation to proper land use; even the word "conservation" had nothing of the meaning that it has

for us today.

     For the sake of ourselves and those who will come after us, we must now set about repairing the

mistakes of our forefathers.Conservation should, therefore, be made a part of everyone's daily life.To

know about the water table (地下水位) in the ground is just as important to us as a knowledge of the

basic mathematic formulas.We need to know why all watersheds need the protection of plant life and

why the running current of streams and river must be made to yield their full benefit to the soil before

they finally escape to the sea.We need to be taught the duty of planting trees as well as of cutting them.

We need to know the importance of big, mature trees, because living_space_for_most_of_man's_fellow_

creatures_on_this_planet_is_figured_not_only_in_square_measure_of_surface_but_also_in_cubic_

volume_above_the_earth.In brief, it should be our goal to restore as much of the original beauty of nature as we can.

1.  The author's attitude towards the present situation in the use of natural resources is ________.

A.  positive  

B.  neutral

C.  critical  

D.  suspicious

2.  According to the author, the greatest mistake of our forefathers was that ________.

A.  they had little or no sense of environmental protection

B.  they had no idea about scientific forestry

C.  they did not know the importance of nature study

D.  they had no idea of how to make good use of raw materials

3.  With a view to correcting the mistakes of our forefathers, the author suggests that ________.

A.  we plant more trees and make full use of the woodlands

B.  we be taught environmental science, as well as the science of plants

C.  we return to nature and not use any natural resources at all

D.  environmental education be directed toward everyone

4.  What does the author imply by saying "living space...above the earth" in the underlined sentence in

      Paragraph 3?

A.  Our living space on the earth is getting smaller and smaller in volume.

B.  We must create better living conditions for both birds and animals.

C.  We need to take some measures to protect space in volume.

D.  Our living space should be measured in cubic volume.

5.  What's the best title for the passage?

A.  Our Forefathers' Big Mistake

B.  Improve the Living Conditions 

C.  Protection of Our Resources 

D.  Lead a Simple Life

下列属于细木工板特点的是( )。

A．质地坚硬、花纹美观

B．用刨花、木屑、木丝、短小废木料等经胶粘热压而成

C．隔声隔热、材质均匀

D．利用木材小料制造大幅面板，可提高木材使用率

E．质量等级分为一等品和二等品

主要由浆细胞合成的血清蛋白是（）

A.α2球蛋白

B.α1球蛋白

C.白蛋白

D.β球蛋白

E.γ球蛋白