2.Since historical times, England, where the early inhabitants were Celts, has been conquered three times. It was conquered by_____________.
A、A.the Vikings, the Anglo-Saxons, and the Normans
B、B. the Romans, the Anglo-Saxons and the Vikings
C、C. the Anglo-Saxons, the Vikings and the Normans
D、D. the Romans, the Anglo-Saxons, and the Normans