In a sentence, some words are stressed more than others.
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Structures words such asa, the, and, but, to, of, it,andyou are usually unstressed. They sound quieter and quicker.
A. 对
B. 错
If a word has more than one syllable, all the syllables are stressed.
A. 对
B. 错
蒸馏操作的依据是混合物中各组分的( )
A. 密度差异
B. 溶解度差异
C. 温度差异
D. 挥发度差异
在精馏塔设计中,若F、xF、xD、xW及R一定,进料由原来的气液混合物进料改为饱和液体,则所需理论板数NT将( )
A. 变大
B. 变小
C. 不变
D. 无法确定