A.頸1-4脊神經(jīng)B.頸2-4脊神經(jīng)C.頸3-4脊神經(jīng)D.頸1-8脊神經(jīng)E.頸5-胸1脊神經(jīng)
A.C1~4脊神經(jīng)的前支組成 B.C2~4脊神經(jīng)的前支組成 C.C1的后支和C2~4脊神經(jīng)的前支組成 D.C2~7脊神經(jīng)的前支組成 E.C2~4脊神經(jīng)的后支組成