神经源性肿瘤好发部位是（）
A.前下纵隔
B.前上纵隔
C.中纵隔上部
D.后纵隔脊柱旁沟内
E.中纵膈下部
参考答案：D
The president of the World Bank says he has a passion for China, ______ he remembers starting as early as his childhood.
A．where
B．when
C．what
D．which
人体组织和体液中，下列哪一项最能使声衰减程度加重（）
A.胆汁、尿液、血液
B.皮下脂肪
C.肝肾实质、肌肉
D.胶原纤维
E.钙质
