I was quite surprised when I read in your letter that you had decided not to finish your studies at the university.
当我在你的信中看到你已决定终止大学学业时感到很是惊讶。
This increases their air-resistance and reduces the shock of impact when they hit the ground.
这样就加大了空气阻力,并减少了它们着地时冲击力带来的震动。