正常肺静脉血流的多普勒频谱有什么特点 A.收缩期、舒张期各有一正向的峰 B.只有舒张

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问题:

正常肺静脉血流的多普勒频谱有什么特点

A.收缩期、舒张期各有一正向的峰
B.只有舒张期一个正向的尖峰波
C.收缩期、舒张期各有一正向的峰,后者大于前者
D.舒张期呈双峰、均正向
E.收缩期呈双峰,均为负向,无舒张期血流

考点:大型设备上岗证考试彩色多普勒(CDFI)上岗考试CDFI医师业务能力考评
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How should one invest a sum of money in these clays of inflation (通货膨胀)? Left in a bank it will hardly keep its value, however high the interest rate. Only a brave man, or a very rich one, dares to buy and sell on the Stock Market. Today it seems that one of the best ways to protect your savings, and even increase your wealth is to buy beautiful objects from the past. Here I am going to offer some advice on collecting antique clocks, which I personally consider are among the most interesting of antiques.

I sometimes wonder what a being from another planet might report back about our way of life. "The planet Earth is ruled by a mysterious creature that sits or stands in a room and makes a strange ticking sound. It has a face with twelve black marks and two hands. Men can do nothing without its permission, and it fastens its young round people's wrists so that everywhere men go they are still under its control. This creature is the real master of Earth and men are its slaves(奴隶)."

Whether or not we are slaves of time today depends on our culture and personality, but it is believed that many years ago kings kept special slaves to tell the time. Certain men were very clever at measuring(量) the time of clay according to the beating of their own hearts. They were made to stand in a fixed place and every hour or so would shout tire time. So it seems that the first clocks were human beings.

However, men quickly found more convenient and reliable(可靠的) ways of telling the time. They learned to use the shadows cast by the sun. They marked the hours on candles, used sand in hour- glasses, and invented water-clocks. Indeed, any serious student of antique should spend as much time as possible visiting palaces, stately homes and museums to see some of the finest examples of clocks from the past.

Antique clocks could be very expensive, but one of the joys of collecting clocks is that it is still possible to find quite cheap ones for your own home. After all, if you are going to be ruled by time, why not invest in air antique clock and perhaps make a future profit(收益)?

小题1:According to the passage, collecting antique clocks____.

A.can hardly keep the value of your savings

B.will cost much of your savings

C.may increase your wealth

D.needs your bravery小题2:By quoting (引用) the remark of a being from another planet, the author intends to____.

A.suggest human beings are controlled by a clock

B.describe why clocks can rule the planet Earth

C.tell readers what clocks look like

D.compare chocks to human beings小题3:Which of the following is NOT mentioned as a way to measure the time?

A.Counting the beating of one's own heart.

B.Making use of candles, sand and water.

C.Observing shadows cast by the sun.

D.Keeping slaves busy day and night.小题4:The underlined phrase stately homes in paragraph(段落)4 means_________.

A.state-owned houses

B.houses in very good condition

C.grand houses open to the public

D.houses where statesmen meet regularly小题5:The purpose of the passage is________.

A.to introduce the culture of antique clocks

B.to offer some advice on collecting antique clocks

C.to compare different ways to make a future profit

D.to explain convenient and reliable ways of telling time

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全国人大代表、升华集团董事长夏士林等向召开的十一届全国人大四次会议建议,加大公民道德建设,完善公民道德教育体系,提升“道德血液黏稠度”。 这是因为,思想道德建设

①体现了先进文化的性质和前进方向

②为我国经济社会发展提供了智力支持

③是发展中国特色社会主义文化的重要内容和中心环节

④能提供精神动力和正确价值观,决定社会发展进程和方向

A.①②

B.①③

C.②④

D.③④

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并非所有服务不足都是下一步服务提升的内容()

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Word中将剪贴板中的内容插入到文档中的指定位置,叫做粘贴。

题型:单项选择题

边际产量递减规律,指在短期生产过程中,在其他条件(如技术水平)不变的前提下,增加某种生产要素的投入,,当该生产要素投入数量增加到一定程度后,再增加该要素所带来的边际产量是递减的(如下图)。假设可变要素投入量为Q,从图中可以推论出()

①Q>B时,边际产量为负值,应增加可变要素投入量

②A<Q<B时,由于可变要素投入量过大,导致总产量减少

③Q=B时,边际产量为0,应优化要素配置、提高效益

④Q<A时,由于可变要素投入量不足,导致边际产量没有实现最大化

 

A、①②

B、①③

C、②④

D、③④

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