盈亏平衡分析的基本原理是根据成本总额对( )的依存关系，全部成本可以分解为固定成本

根据短文内容，从短文后的七个选项中选出能填放空白处的最佳选项。选项中有两项为多余选

项。

Why Cats Scratch Tings

In has long been assumed that when cats scratch objects with their front paws（爪子）that they are sharpening their claws.   1 Research on cat behavior suggests that the major reason for this behavior is communication. By scratching up the bark of a tree (or the leg of your favorite chair) the cat is letting other cats or people know where she is and what she is up to.

Cats tend to pick a small number of noticeable objects in their environments to scratch such as trees, fence posts repeatedly.  2 The scratched surface leaves a highly visible mark that can be easily seen by other cats. In addition, cats have special glands （腺）in their paws so that when they make scratching movements they leave scent（气味）that the cats can smell. The fact that cats leave scent marks by making scratching movements may be the reason that cats will continue to scratch objects even after they have been declawed.  3 

We don’t know exactly what cats are communicating with their scratching. Both males and females do it. It is done inside and outside the home and even by cats living with no other cats around.  4  Cats don’t scratch up your furniture to bother you or just to be destructive, but for specific reasons, one of which is communicating. Cats also scratch to extend their bodies, during play, and possibly as a greeting or to relieve dissatisfaction when prevented from doing other things they want to do.

  5 It is easier to prevent problem scratching rather than trying to change your cat’s preference for the arm of your sofa after it has become a built up habit. Thus, the goal is to establish acceptable scratching habits by getting your cat to prefer a scratching post rather than the arm of your sofa.

A．It turns out that this is only a secondary reason.

B．This is why the tree next door looks so scratched up.

C．Cats use other parts of their bodies to communicate as well.

D．Small pieces of bark have accumulated on the ground underneath.E．Scratching can result in considerable damage, owner dissatisfaction.

F．Declawed cats may still be leaving scent marks on objects they scratch.

G．It could be a defensive warning or just a marker that announces its existence.

一件上衣48元，全用10元一张的人民币付款，至少要用（    ）张10元的人民币。

下图表示设计变更处理流程，标示③处应为（）。

A．设计单位提出设计变更

B．总监签发设计变更

C．监理工程师评估工程变更赞用及工期

D．业主认可

(每空2分，共10分)学习完植物的生理作用的相关知识后，某兴趣小组精心设计了如下实验进行验证。请你分析回答：

①取盆栽牵牛花植株放在暗处一昼夜后，将植株枝条上长势、大小均相同的三个叶片分别置于ABC三个透明塑料软瓶内，密封瓶口，其他处理如图，然后将甲装置整体移至光下6小时；

②分别将A、B、C瓶的导管伸入澄清石灰水中，打开阀门，轻挤塑料瓶，观察石灰水的变化

③取出三瓶内的叶片，分别用乙装置脱色，然后漂洗干净并滴加碘液观察颜色变化。

（1）甲装置中，A与B可以构成一组对照实验，其变量是                               。

（2）从A瓶中挤出的气体可以使澄清的石灰水变浑浊，其原因是：该瓶气体中含有较多的二氧化碳，这是叶片进行                    作用产生的。

（3）用乙装置脱色时，小烧杯内盛放的液体是                     。

（4）滴加碘液后，变为蓝色的是取自          瓶的叶片。该实验可以证明：绿叶制造淀粉时需要光照和             。

外伤致完全变性反应者自发恢复的______甚小；部分变性反应者自发恢复的____大些；神经失用者一般可能____。