o Since the industrial revolution began the physical science has in general been in the forefront of the scientific movement 自从工业革命开始以来,物理学总的说来 一直处于科学运动的前列。(时态) Then the whole course of my life might have been different 如果真是那样的话,我的生命路程也许是 另一番景象。(虚拟语气)⚫Since the industrial revolution began the physical science has in general been in the forefront of the scientific movement. 自从工业革命开始以来， 物理学总的说来 一直处于科学运动的前列。（时态） Then the whole course of my life might have been different. 如果真是那样的话，我的生命路程也许是 另一番景象。（虚拟语气）