21 身體內主要存在於肝臟、腎上腺及造血器官的微血管類型屬於:(A)連續型微血管(continuous capillary)(B)竇狀型微血管(sinusoidal capillary)(C)障壁型微血管(barrier capillary)(D)開窗型微血管(fenestrated capillary)