I-7：it's survival of the fittest 适者生存
A:Where is John studying?
A:约翰在哪儿上学？
B:He's at the Seals Naval Academy.
B：席尔斯海军学院。
A:How is he getting along there?
A:他在那儿混得如何？
B:He's having a hard time. It's survival of the fittest.
B：可不好混哦，那可是个适者生存的世界。
