With a great weight ________ off her mind, she passed all the tests successfully.

A．taking

B．taken

C．to take

D．being taken

关于结肠的结构特征，错误的是（）

A.黏膜不形成环形皱襞

B.杯状细胞含量多

C.黏膜无绒毛

D.肠腺排列紧密

E.柱状上皮表面有纹状缘