单项选择题A．Hyde ParkB．Downing StreetC．Times SquareD．Trafalgar Square

填空题early September

单项选择题A．post-graduate studentsB．senior university studentsC．professionalsD．teachers of history

单项选择题A．underwater explosionsB．oil and gas explorationC．whistling of shipsD．sonar navigation

单项选择题A．in FebruaryB．in MarchC．in AprilD．in May