对精馏塔而言,回流比大,塔顶馏出组分纯度()。
A、低
B、高
C、无影响
参考答案:B
We will keep you _____ of our progress and look forward to hearing from you..[ ]
A. heard
B. informed
C. realized
D. recognized
不锈钢管通球试验时,则可采用等于管子内径()的木球或不锈钢球做通球试验。
A.70%
B.86%
C.90%
D.76%