Maybe if I _______ literature, but not science then, I would be able to give you more advice now.

A．studied

B．would study

C．had studied

D．was studying

甲、乙两列火车，车长分别为L₁和L₂，在相邻的两条平直轨道上，甲车以速度v₁向东匀速行驶，乙车以速度v₂也向东匀速行驶，已知v₂＞v₁，则乙车从追上甲车到离开甲车的时间为______．