气相色谱分析采用恒温—线性—恒温程序升温的作用是什么?
参考答案:
初始用恒温分离低沸点组分,然后线性升温至终温,在终温保持一定时间,把高沸点组分冲洗出来。
已知起航点经度λ1=065°24'.6E,两地间的经差Dλ=106°30'.0W,则到达点经度λ2为()。
A.171°54'.6E
B.041°05'.4E
C.171°54'.6W
D.041°05'.4W
Look out! The traffic is _____ fast _____ we can't cross the street now. [ ]
A. too; to
B. enough; to
C. so; that
D. such; that