题目

●Tower Bridge is one of London’s most well known landmarks. Opened in 1894, this hydraulic(液压的)  bridge can be raised to permit river traffic to pass underneath.        Visitors to Tower Bridge can enjoy wonderful views of the River Thames from the bridge towers. There is also a museum which explain how the bascule bridge operates and discusses its history. Tower Bridge is often incorrectly referred to as London Bridge. London Bridge, however, is a different bridge that is located directly upstream from Tower Bridge.        ●The British Museum is a “must do” for al已知全集U={1，2，3，4，5，8}，集合A={2，4}，B={2，4，8}，C={2}，D={4，8}，求：①A∩B；  ②B∪C；  ③（∁UA）∩C；  ④∁U（C∪D）