第九章 World Wars 两次世界大战 萨拉热窝事
书迷正在阅读：神级扮演：从小丑开始、地下城之主、全球天选：开局觉醒百倍经验天赋、妖魔入侵：我成救世大剑仙、名侦探柯南续集、火影：等会，我先戴个写轮眼、神奇宝贝之无尽轮回、这个世界的穿越者有点多、异界游戏王之虚空变、潜伏火箭队，只为超梦
ricted submarine warfare， realising the Americans would eventually enter the war. Germany sought to strangle Allied sea lanes before the U.S. could transport a large army overseas， but were only able to maintain five long range U–boats on station， to limited effect. ??The U–boat threat lessened in 1917， when merchant ships began travelling in convoys escorted by destroyers. This tactic made it difficult for U–boats to find targets， which significantly lessened losses; after the introduction of hydrophone and depth charges， accompanying destroyers might attack a submerged submarine with some hope of success. The convoy system slowed the flow of supplies， since ships had t