在HPLC中,范氏方程中的哪一项对柱效能的影响可以忽略不计()
A.涡流扩散项
B.分子扩散项
C.动态流动相传质阻力项
D.静态流动相传质阻力项
参考答案:B
Light-to-moderate smokers were ________ to die of sudden heart problems than those who had never smoked.
A.as twice likely
B.twice more possible
C.twice more likely
D.as twice possible
车站应设在平道上,必须设在坡道上时,其坡度一般不得超过()。
A.6‰
B.2.5‰
C.2‰
D.1‰