如图,这是泡沫灭火器工作时的模拟实验.请你根据所学物理、化学知识简述其中的工作原

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问题:

如图,这是泡沫灭火器工作时的模拟实验.请你根据所学物理、化学知识简述其中的工作原理和灭火原理.写出有关反应的化学方程式.

考点:灭火的原理和方法化学反应方程式的书写文字表达式
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任何商品的替代效应总是为正值,收入效应则根据商品的特点,有的为正值,有的为负值。( )

题型:问答题

被称为伊斯兰世界建筑经验的结晶的建筑是()。

题型:问答题

县城竞有如此优秀花旦,真令人意想不到!()那精湛演技、圆熟唱功,真看不出她是第一次登台演出。而当她一声长叹,背身蓦然往观众座席回眸一顾时,整个现场立刻(),静得听得见针掉地下的声音。

填入括号最恰当的一项是:

A.何况 万籁无声

B.况且 万籁无声

C.何况 鸦雀无声

D.况且 鸦雀无声

题型:问答题

EBCT是以下哪种CT的缩写()

A.螺旋CT 

B.CT血管造影 

C.电子束CT 

D.高分辨力CT 

E.普通CT

题型:问答题

Which of the following statements about theories of the yield curve is most likely correct()

A. A liquidity preference cannot be consistent with a flat term structure of interest rates.  B. The liquidity preference theory suggests that a downward-sloping term structure of interest rates is due to investors expecting short-term rates to decline, and although there is a maturity premium to consider, it is not large enough to offset the expectation of declining short-term rates. 

C. The pure expectations theory suggests that an upward-sloping term structure of interest rates is a consequence of investors expecting short-term rates to remain unchanged for a period of time, followed by investors expecting short-term rates to rise for a period of time.

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