牙科X线片中，最阻射X线的组织是（）
A.牙骨质
B.牙本质
C.牙槽骨
D.牙釉质
E.牙髓
参考答案：D
肺炎合并感染性休克最常见的致病微生物是（）
A.肺炎球菌
B.克雷白杆菌
C.支原体
D.病毒
E.革兰阴性杆菌
She was_______ to find the book she had looked forward to had been sold out. [ ]
A. cast aside
B. cast down
C. cast up
D. cast about
