下列何者為小腸之內襯上皮？(1)無纖毛之單層柱狀上皮(nonciliated simple columnar epithelium)(2)單層扁平狀上皮(simple squamous epithelium)(3)偽多層柱狀上皮(pseudostratified columnar epithelium)(4)移形上皮(transitional epithelium)
(A)(1)
(B)(2)
(C)(3)
(D)(4)

小腸上有許多用於吸收前面消化道酵素分解後...