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问题 填空题

从C、H、O、Na 四种元素中，选择适当的元素，组成符合下列要求的化合物的化学式。

答案

H2（或C、O2、Na）； H2O（或CO2、CO、H2O2、Na2O）； H2CO3； NaOH （答案不唯一）

完形填空

A. watched    B. weak     C. studied   D. love   E.  than
  “I first heard about Mother Teresa in my high school, we   小题1: a video about her work in India and all over the world. I was so moved by her spirit to help others and her endless   小题2:  for every human being that after I graduated from high school, I also wanted to try her kind of work. So with two friends I flew to Calcutta for a few weeks.”
“I was asked to work in a home for sick people. I helped wash clothes and sheets, and pass out lunch. I also fed the people who were too   小题3:  to feed themselves and tried to cheer them up. I felt it was better to share with them   小题4: to think that I have helped them. To be honest, I don’t think I was helping very much. It was then that I realized that I had not really come to help, but to learn about and experience another culture that helped improve my own understanding of life and the world.”
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单项选择题

Sequential circuit is a common logic device whose output values, at a given instant, depend upon its input values and the internal state at that instant, and whose internal state depends upon the (66) preceding input values and the preceding internal state. A sequential circuit can assume a finite number of internal states and may therefore be regarded, from an abstract (67) , as a finite (68) .

Combinational circuit is another logic device whose output values, at any given instant, depend upon the input values at that instant. A combinational circuit is a (69) of a sequential circuit whose internal state is not taken (70) .

（66）处填（）。

A．directly

B．immediately

C．instantly

D．snapshot
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