朋友代他承诺参加跳伞训练。

He was volunteered for parachute training by friends.

出事那天，他在空军基地，负责跳伞训练。

He was at the military airbase that fateful day, in charge of parachute training.

目的研究跳伞训练对新老兵应激程度和某些免疫指标的影响.

Objective To observe the paratroop training stress effect on blood cortisol and antibody of paratroopers.