ARDS初期的临床特点是( )。 A．呼吸费力 B．无明显低氧血症 C．无明显发绀

常温下，下列各组离子一定能大量共存的是（　　）

A．Na⁺、K⁺、Cl^-、CH₃COO^-

B．Ba²⁺、K⁺、SO₄^2-、CO₃^2-

C．Al³⁺、K⁺、CO₃^2-、Cl^-

D．Na⁺、Fe³⁺、Cl^-、SO₄^2-

黄连汤证的主证是（）

A.心下痞硬，噫气不除

B.心下痞，呕吐下利

C.腹中痛，欲呕吐

D.腹中痛，下利不止

E.腹中雷鸣下利

如果你是宋朝一位管理海外贸易的官员，你的职务是[ ]

A．转运使

B．盐运使

C．市舶司

D．节度使

在证券经纪业务营销中，证券公司集中性市场营销策略可分为( )。

A．地区集中策略

B．时间集中策略

C．品种集中策略

D．客户集中策略

I love science and science fiction. Like many science fiction fans, I am fascinated by the possibility of time travel. However, one must combine romance with reasoning and look into the chances of time travel critically.

First of all, we must remember the whole universe is in motion. If we want to go back to yesterday, our "time machine" has to move back in time and space. If someone claimed he was at home when he suddenly travelled 200 years back in time, he either had an illusion or made the story up. Two hundred years ago, Earth was in a different place in space, so how can you travel back 200 years without moving in space? Don't get me wrong. I am not knocking the genius of science fiction writers. H.G. Wells's "The Time Machine" is a great work of fiction, but that’s all. I have read many other time travelling science fiction stories since reading H.G. Wells, but none address this problem of displacement.

My own argument for the impossibility of time travel is that physical states of the past no longer exist and those of the future are not here yet. To be able to move back and forth in time requires everything that has happened, is happening, and will happen everywhere in the whole universe at every single moment in time－past, present, and future－to be stored as a "reality" somewhere－like the save game file of a computer game that contains every single byte of information of the game at the point it was saved, but you would need an almost extremely large file and almost extremely many of them－so it can be re-entered and communicated with, and not just light signals for viewing. To me, I don’t buy it.

小题1:Which of the following can be the best title?

A．How to make time travel possible?

B．Why am I fascinated by time travel?

C．Why do I think time travel is not possible?

D．How to explain the possibility of time travel?小题2:What’s the meaning of the underlined word “illusion”?

A．success

B．dream

C．switch

D．support小题3: According to the author, which of the following is RIGHT?

A．We can go back to the past by time travel.

B．People can travel to the future by moving in space.

C．“The Time Machine” is nothing more than a science fiction.

D．Everything that happened, is happening and will happen can be stored somewhere.小题4:In the author’s opinion, time travel might be possible if                            .

A．people could combine romance with reasoning

B．people could stop the movement of the whole universe

C．people could use time machine under the instruction of H.G. Wells

D．people could “save” everything in the past, present and future in a certain space