地黄的道地产区是（） A.广东 B.吉林 C.河南 D.云南 E.宁夏

曲线y=-x²+4x上有两点A（4，0）、B（2，4）．

求：（1）割线AB的斜率k_AB及AB所在直线的方程；

（2）在曲线AB上是否存在点C，使过C点的切线与AB所在直线平行？若存在，求出C点的坐标；若不存在，请说明理由．

根据短文内容，从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

(Linguistic(语言学的) Puzzles

     How did language begin? What was the world's first language? Do all languages come from one

original language?   1._____.

     In the 4th century BC, the Greek historian Herodotus wrote this account: Psamtik  I,an Egyptian

King, wanted to find out what the oldest language in the world was.  2.____.He told his servant to find

two newborn babies. When the servant had found them, the king gave them to a shepherd (牧羊人) and

said, "Keep these babies with the goats. Take care of them, but do not talk to them. Listen to any words

that they say." The king wanted to find out what language the children would speak if they were left alone. He said, "The first words they speak will come from the original language of the world."

     3._____  . He told the king who asked his scholars about this word. They told him that the Phiygians, who lived in an area which is now Turkey, called bread "becos".The king said, "Then Phiygian is the

oldest language." Today we know that the king's conclusion was wrong. We don't know why the children

said "becos".

      4._____. Scholars discovered that many European and southern Asian languages belonged to the

same "family" and that they started from the same parent language, ProtoIndoEuropean. Linguists think

that it had split into several different languages, including Greek and Sanskrit, between 2000 and 1000

BC. Other languages, such as English and Spanish, developed from later splits.

     5._____ . Two questions that interest linguists are: How does language change? Why does language

change? If you like solving mysteries, historical linguistics may be the job for you.

A. Nowadays, we study the origin of language more scientifically

B. He was talking about this problem with his scholars when he had an idea

C. The King was very kind to his servant and his servant remained royal to him

D. Linguists are the scholars who are very interested in categorizing the language families

E. People have been trying to find the answers to these questions for more than 2000 years

F. One day, while the babies were babbling to each other, the shepherd heard them say "becos"

G. Linguists have classified many language families, and they are still trying to categorize others

确诊流脑最重要的依据是（）

A.冬春季节发病，有皮疹、脑膜刺激征

B.脑脊液成化脓性改变

C.脑脊液涂片革兰染色发现阴性球菌

D.血或脑脊液培养阳性

E.咽拭子培养阳性

全面质量管理在早期称为（），以后随着进一步发展而演化称为（）。

2011年2月21日，某化工厂发生一起火药爆炸事故，造成22人死亡，3人受伤，约200m²及部分机器设备被炸毁，直接经济损失40.48万元。
事发当时，该厂84^＃车间条装工序一螺旋输送器空心螺杆在运行中断裂，车间副主任熊××(事故中死亡)了解情况后，为了不影响生产，在生产继续进行，现场人员未撤出的情况下，违章指挥无证焊工甲(事故中死亡)焊接输送器。专职安全员乙即到厂部办理“动火证”。因安全科2名干部及4名正副厂长均因工外出，乙便自己写了一张“84^＃车间需要动火，条装工序一螺旋动火焊接”的便条动火证，去找厂办主任丁审批。丁说自己无权审批，便与乙一起找到厂工会 * * 丙。丙便在便条动火证上签署了“同意动火，注意安全”，越权擅自批准动火。乙回到车间，将丙签发的便条动火证交给甲，并对欲焊接处0.7m²范围内的炸药进行清扫、冲洗。然后，由乙同意并监护无证焊工甲焊接螺旋输送器螺杆。约20分钟后，乙发现空心螺杆内有残存炸药，并有大量烟雾从断裂处喷出，但甲认为：“炸药清洗不出来，没办法，可能问题不大”。乙便用水冲洗螺杆降温，甲进行违章施焊。乙因事离开车间。约10分钟后，该车间发生爆炸。

根据以上场景，回答下列问题：

这起事故中存在的物的不安全状态和人的不安全行为分别是什么