在空间中有如下命题:①互相平行的两条直线在同一平面内的射影必然是互相平行的两条直

题型:选择题

问题:

在空间中有如下命题:
①互相平行的两条直线在同一平面内的射影必然是互相平行的两条直线;
②若平面α平面β,则平面α内任意一条直线m平面β
③若平面α与平面β的交线为m,平面α内一条直线n⊥直线m,则直线n⊥平面β
④若点P到三角形的三个顶点距离相等,则点P的该三角形所在平面的射影是该三角形的外心
其中正确的命题个数是(  )
A.1B.2C.3D.4
考点:空间中直线与平面的位置关系平面与平面的位置关系
题型:选择题

明太祖为巩固统治,他对子孙采取的措施是[ ]

A、到中央各部做官  

B、一心只读圣贤书

C、分封到各地做藩王

D、侍候皇上

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阅读理解。

     阅读下面短文,并根据短文后的要求答题(请注意问题后的字数要求).

     Modern inventions have speeded up people's lives amazingly. Motor cars cover a hundred miles

in lithe more than an hour,aircraft cross the world inside a day,while computers operate at lightning

speed. Indeed,this love of speed seems never ending. Every year motor cars are produced which g

o even faster and each new computer boasts(吹嘘)of saving precious seconds in handling tasks. 

     All this saves time,but at a price. When we lose or gain half a day in speeding across the world in

an airplane,our bodies tell us so. We get the uncomfortable feeling known as j et lag; our bodies

feel that they have been left behind in another time zone. Again,spending too long at computers results

in painful wrists and fingers. Mobile phones also                    ,according to some scientists;too much

use may put harmful radiation into our brains,a consequence we do not like to think about.

     However,what do we do with the time we have saved? Certainly not relax,or so it seems. We are

so accustomed to constant activity that we find it difficult to sit and do nothing or even just one thing at

a time. Perhaps the days are long gone when we might listen quietly to a story on the radio,letting

imagination take us into another world.

     There was a time when some people's lives were devoted simply to the cultivation(耕耘)of the land

or the care of cattle. No multi tasking there;their lives went on at a much gentler pace,and in a familiar

pattern. There is much that we might envy about a way of life like this. Yet before we do so,we must

think of the hard tasks our ancestors faced:they farmed with bare hands,often lived close to hunger,and

had to make tools from wood and stone. Modern machinery has freed people from that primitive

existence.

1. What's the passage mainly about?(within 10 words)

                                                                        

2. List the difficulties our ancestors met according to the text. (within 15 words)

                                                                        

                                                                        

                                                                        

3. Fill in the blank in the 2nd paragraph with proper words or phrases. 

                                                                        

4. Why do we make new products more and more time-saving according to Paragraph 1 of this passage?

                                                                        

5. Translate the underlined sentence in the 3rd paragraph into Chinese. 

                                                                         

                                                                        

题型:选择题

对肾动脉狭窄最有诊断价值的是()。

A.病史

B.体格检查

C.超声检查

D.肾动脉造影

E.螺旋CT血管造影

题型:选择题

《淮北矿业关于2015年安全生产体系建设的指导意见》规定,牵头领导负责所牵头要素的组织领导和建设推进工作,各副总协助相应分管领导开展工作;督促指导责任部门全面完成承担()的建设任务。

A、要求

B、要务

C、任务

D、要素

题型:选择题

结构中含有氟元素的甾体激素为

A.醋酸地塞米松
B.醋酸泼尼松
C.黄体酮
D.甲睾酮
E.雌二醇

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