The scientists claimed( 声称) to _______ a jet plane that uses atomic energy as propelling _____, but they can’t produce an atom of evidence to prove it.

　 A. design; power　 　　　　　　　　　　　　B. have designed; power　

C. design; force　 　　　　　　　　　　　　 D. have designed; strength

阅读理解

　　Usually social scientists have greater difficulty in their research work than physical scientists. By that I do not mean to belittle (cause to seem unimportant) the great achievements of physical scientists, who have been able, for example, to describe the atom(原子) without seeing it. That is a splendid achievement, yet in many ways it is not so difficult as what social scientists are expected to do. The conditions under which social scientists must work would drive a physical scientist mad. Here are five of those obstacles (障碍) . He can make few experiments, he cannot measure the results exactly, he cannot control the conditions surrounding the experiments, he is often expected to get quick results with low-acting economic force, and he must work with people, not with objects.

(1)According to the writer, social scientists ________.

[　　]

A．make more achievements to society than physical scientist

B．have settled more problems than physical scientists

C．are no more important than physical scientists

D．face more obstacles than physical scientists in their research work

(2)A physical scientist would find the restrictions (限制) laid upon social scientists ________.

[　　]

A．difficult for him to manage

B．quite easy to deal with

C．like those in his own field

D．helpful to his scientific experiments

(3)The underlined word “that” in the passage refers to ________.

[　　]

A．“difficulty” in the first sentence

B．the first sentence as a whole

C．“to belittle the great achievements of physical scientists” in the second sentence

D．“the atom” in the second sentence

(4)The discovery of the atom by physical scientists is ________.

[　　]

A．not so remarkable as the achievements of social scientists

B．more valuable than what social scientists have ever got

C．their greatest achievement

D．a great achievement of theirs

(5)The conditions under which a social scientist must work are characterized by ________.

[　　]

阅读下列短文，从所给的四个选项中，选出最佳答案

　Scientists had long dreamt of splitting the atom(原子) and let out some of its huge quantity of energy．They didn't find out how to do it until the 1940s．

　Uranium is one of the matters whose atoms can be split fairly easily．A small particle(粒子) is added to an atom of uranium, which then breaks into two smaller atoms．The change has other results．It makes the uranium very hot．It also produces two or there free particles of the kind first added．These free particles move around, splitting other uranium atoms, and so begins a “chain reaction”(链式反应), which produces more heat and more free particles．Both the heat and the chain reaction are important．

　A gas or a liquid is sent into the reactor（反应堆）to collect and carry away the heat．It is used to boil water, and the steam so produced drives the machinery which produces electricity．The chain reaction allows the process(过程) to continue．The reaction, which could be very rapid, is slowed down by a certain matter, which surrounds the fuel．

　Today, many people are wondering how long the world's store of coal and oil will last．Both these fuels, like uranium, are producers of heat energy．Is atomic energy the answer to the world's energy problem?

(1) Which of the following words can take the place of the underlined word“splitting”?

[　　]

A．joining　　　　B．choosing

C．breaking　　　D．heating

(2) What will never happen when a small particle is added to an atom of uranium?

[　　]

A．Two more atoms will appear

B．The atom will split in two and let out energy．

C．More free particles will be produced．

D．The uranium will become very hot．

(3) “Chain reaction”means______．

[　　]

A．free particles produced in the reaction will split other atoms, which in turn will produce more free particles

B．free particles will split more atoms after splitting some atoms

C．atoms split by free particles will continue to split

D．reaction can go on and on with the help of a chain of particles

(4) Which of the following orders shows rightly how a nuclear (原子能的) power plant works?

[　　]

a．Heat is made to boil water．

b．The machinery produces electricity

c．The chain reaction produces heat．

d．Heat is collected and carried away by a gas or a liquid．

e．Steam so produced drives the machinery．

A．d-c-e-b-a　　　B．c-d-a-e-b

C．b-d-e-a-c　　　D．c-a-d-b-e

(5) What fact does this passage lead you to believe?

[　　]

A．Many people wonder whether the world's store of coal and oil will last long．

B．Coal, oil and uranium are fuels, which can produce heat．

C．The world's store of coal and oil will last a very long time．

D．Atomic energy has given people hope to solve the world's energy problem．

    Located about 93 million miles    4    the earth, the sun has a diameter (直径) that is nearly equal to 109 of our ear ths    5    up like a row of beach balls, and a mass that is about 330 000 times the mass of the earth.

    The sun is the original source of nearly all our    6   . It is mostly made of hydrogen (氢), 7    it also contains nearly every other kind of atom (原子 )that exists on the earth. The sun obtains its energy from a process of fusion (溶解) in which hydrogen atoms are changed into helium (氦) atoms    8    extreme heat and pressure. This process creates a great noise, but we cannot hear it because    9    does not travel through empty space.

    Our sun is not even    10    large or bright compared to    11    stars. Stars vary in size from smaller than the earth to large enough to hold a good part of our solar system (太阳系)! The    12    of a star shows its temperature. A star may be red, yellow, white, or blue.

    The nearest star is 4.3 light years from the earth. A light year is the    13    light travels in one year, or about    6    million miles. The    14    stars are billions of light years away. Some are    15    far away that if they were to blow up today, their light would continue to be seen from the earth    16    a million years! Our sun is part of a great galaxy (星系) of    30  billion stars called the Milky Way.    17  , there are billions of galaxies within    18    of our telescopes and countless billions beyond. The bigness of space quite __19  human comprehension. How exciting it is to live in an age    20    human beings have begun to explore that space.

    1．

A. cold　　　　　　　　　　　　   B. hot

C. cool　　　　　　　　　　　　   D. warm

    2．

A. solid　　　　　　　　　　　　   B. water

C. steam　　　　　　　　　　　　 D. air

    3．

A. surface　　　　　　　　　　   B. center

C. middle　　　　　　　　　　    D. bottom

    4．

A. away　　　　　　　　　　　　  B. from

C. far　　　　　　　　　　　　　　 D. within

    5．

A. lined　　　　　　　　　　　　   B. stood

C. put　　　　　　　　　　　　　　 D. tied

    6．

A. food　　　　　　　　　　　　   B. things

C. energy　　　　　　　　　　    D. lives

    7．

A. however　　　　　　　　　　 B. while

C. although　　　　　　　　　　 D. even if

    8．

A. under　　　　　　　　　　　　 B. by

C. of　　　　　　　　　　　　　　  D. with

    9．

A. explosion　　　　　　　　    B. noise

C. voice　　　　　　　　　　　　  D. sound

    10．

A. very　　　　　　　　　　　　   B. relatively

C. specially　　　　　　　　　　 D. especially

    11．

A. another　　　　　　　　　　   B. other

C. others　　　　　　　　　　　　 D. the others

    12．

A. surface　　　　　　　　　　   B. bigness

C. color　　　　　　　　　　　　  D. light

    13．

A. distance　　　　　　　　　　  B. space

C. time　　　　　　　　　　　　   D. place

    14．

A. farthest　　　　　　　　　　   B. smallest

C. biggest　　　　　　　　　　   D. nearest

    15．

A. too　　　　　　　　　　　　　　 B. such

C. quite　　　　　　　　　　　　   D. so

    16．

A. for　　　　　　　　　　　　　　 B. with

C. in　　　　　　　　　　　　　　   D. by

    <
/
span>17．

A. But　　　　　　　　　　　　　　 B. Beside

C. Nevertheless　　　　　　   D. In addition

    18．

A. distance　　　　　　　　　　  B. range

C. time　　　　　　　　　　　　   D. space

    19．

A. beyond　　　　　　　　　　   B. outside

C. out of　　　　　　　　　　　　 D. far from

    20．

A. where　　　　　　　　　　　　 B. when

C. which　　　　　　　　　　　　 D. because