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问题 不定项选择

一个原子核在中子的轰击下发生一种可能的裂变反应，其裂变方程为，则下列叙述正确的是[      ]

A．X原子核中含有86个中子

B．X原子核中含有141个核子

C．因为裂变时释放能量，根据E=mc2，所以裂变后的总质量数增加  

D．因为裂变时释放能量，出现质量亏损，所以生成物的总质量减少

答案

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单项选择题

非结算会员向期货交易所支付的手续费，由（）从全面结算会员期货公司期货保证金账户中划拨。

A．期货公司

B．中国银行

C．中国证监会

D．期货交易所
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完形填空

第二节：短文填词（共10小题，每小题1分，满分10分）

1.           
2.           
3.           
4.        
5.           
6.            
7.            
8.            
9.       
10.       

 
No one knows exactly how the earth began, as it happened

so long ago. However, according to a widely accepted     (理论),
the universe began with a “Big Bang” that threw matter
      all directions.  After that, atoms began to
     (形成) and combine to create stars and other bodies.
For several b     years after the “Big Bang”, the earth was
still just a cloud of dust. What it was to become w   uncertain
until between 4.5 and 3.8 billion years ago when the dust
settled into a solid     (球体) . The earth became so violent
      it was not clear whether the shape would last
      not. It exploded loudly with fire and rock. They were in
time to produce carbon, nitrogen, water vapor and other
gases, which were to make the earth’s          (大气层).
What is even more important is that as the earth   down(冷却下来),
water began to appear on its surface.
( Big Bang: 宇宙大爆炸)
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