如果根动脉血流障碍，易引起哪些节段的脊髓缺血坏死而发生截瘫（）

A.T₄或L₁

B.T₆或L₃

C.T₁₀或L₂

D.C₆或T₄

E.C₅或L₃

So far, the moon is the only one of the heavenly bodies in space ______ reached by manned spaceships.

A．that has been

B．what have been

C．which has been

D．that have been