Summary: British police have arrested a seventh person over the suicide attack in Manchester, as they investigate what they're calling a "terrorist network" behind the blast. Twenty-two people were killed, including children, and another 6... (英国警方逮捕了跟曼彻斯特演唱会炸弹袭击案有关的第7人。警方称，在这次爆炸案的背后有一个恐怖分子的网络。截至发稿时为止，这起当地时间周一晚间发生的袭击事件已经导致包括儿童在内的22人死亡，64人受伤。请听记者吴音的报道。 )
