Mike came here _____ to see you, _____ after he heard that you had retumed from abroad. [ ]

A. especially; specially

B. especially; especially

C. specially; especially

D. specially; mainly

在硅油柱上苯与环己烷的保留时间分别是330s和365s，测得两个峰的半峰宽分别是0.5cm和0.8cm，已知记录器的纸速为2.0cm/min。试求分离度R两个峰是否完全分开.