About the corticospinal tract, which of the following descriptions are correct.（ ）
A.It originates from the giant pyramidal cells (锥体细胞) of superior and middle parts of primary soma B.It passes through the posterior limb of internal capsule (内囊后肢). C.In the mesencephalon, it is situated in the intermediate 3/5 of crus cerebri (大脑脚底). D.In the medulla oblongata, it located deep to the pyramid. E.At the level of inferior end of medulla oblongata, the small part of the cordicospinal tract crosses正确答案ABCD
