将下列语句依次填入文中的横线处,使上下文语意连贯。衔接最恰当的一组是( ）几十年来,霍金的身体禁锢在轮椅中,_____,_____,_____,_____。他以极度残疾之身,取得极其辉煌的科学成就,成为自爱因斯坦以来引力物理学领域最大的权威。①他执著地寻求着“我们从何处来,我们往何处去”的答案②震动了整个理论物理学界③发现了一个又一个宇宙运行的重大奥秘④思维却遨游于广袤的太空

I’m terribly sorry to turn you down this time, but I promise I will ________ to you next time.

k it’s not in the length of days, but inthe use we make of them_____ the value of life lies

It’s too hard for me to pass the exam. —Never ______. Believe in yourself!

Farmers in China began to use tractors ___cattle for farming work.