中枢免疫器官包括（）
A.淋巴结和脾脏
B.骨髓、胸腺和腔上囊
C.淋巴结和胸腺
D.骨髓和黏膜相关淋巴组织
E.淋巴结和骨髓
参考答案：B
Is this your brother? What's ______ name? [ ]
A. her
B. his
C. your
光固化复合树脂充填时，分层光照的厚度不超过
A．0.5mm
B．1.0mm
C．1.5mm
D．2.0mm
E．3.0mm
