锥度的标注用符号表示，符号所示方向与锥度方向（）.

每辆车限乘48人，60人需要1.25辆车．______．（判断对错）

已知有机物 A、B、C、D、E、F之间的转化关系如图所示。D 是常用做汽车发动机的抗冻剂，E为聚合物，F的式量为26。根据信息回答下列问题。

(1) 写出A中官能团名称             

(2)  B转化为C的反应类型                  

(3) 有机物D具有以下哪几方面的化学性质：             （填序号）

①  加成反应 ②取代反应 ③消去反应  ④氧化反应  ⑤ 还原反应

(4)  E的结构简式为                 

(5)  C—F反应的方程式                        

Observe that for the programmer,as for chef, the urgency of the patron（顾客）may govern the scheduled completion of the task,but it cannot govern the actual completion.An omelette(煎鸡蛋),promised in two minutes,may appear to be progressing nicely.But when it has not set in two minutes,the customer has two choices-waits or eats it raw.Software customers have had （）choices.

Now I do not think software（）have less inherent courage and firmness than chefs,nor than other engineering managers.But false（）to match the patron’s desired date is much more common in our discipline than elsewhere in engineering.It is very（）to make a vigorous,plausible,and job risking defense of an estimate that is derived by no quantitative method,supported by little data,and certified chiefly by the hunches of the managers.    Clearly two solutions are needed.We need to develop and publicize productivity figures,bug-incidence figures,estimating rules,and so on.The whole profession can only profit from（）such data.Until estimating is on a sounder basis,individual managers will need to stiffen their backbones and defend their estimates with the assurance that their poor hunches are better than wish derived estimates.

It is very（）to make a vigorous,plausible,and job risking defense of an estimate that is derived by no quantitative method,supported by little data,and certified chiefly by the hunches of the managers.

A．easy

B．difficult

C．simple

D．painless

屈光参差指双眼屈光度相差（）。

A.1.0D以上

B.2.0D以上

C.3.0D以上

D.4.0D以上

E.5.0D以上

在Windows XP中，“磁盘碎片整理程序”的主要作用是______。

A．修复损坏的磁盘
B．压缩磁盘中的文件
C．提高文件访问速度
D．释放磁盘空间