The cerebral arterial circle is formed by which of following arteries.（ ）
A.anterior communicating artery (前交通动脉) and posterior communicating arteries B.original portions of the anterior cerebral arteries (大脑前动脉) C.original portions of the middle cerebral arteries D.original portions of the posterior cerebral arteries E.terminal prtions of the internal carotid arteries正确答案ABDE
