【正确答案】 A

【答案解析】句意：如果没有现代通讯，我们必须等若干周后才能得到世界各地的新闻。本题考查的是虚拟语气。将句子还原为：If there were no modern telecommunications，we would have to wait for weeks to get news from around the world．根据倒装规律，if去掉时，were要提前。因此答案选A。