A．
B．
C．
D．
答案：D
Many streets in this city have been ________ for cultural protection.[ ]
A. stretched out
B. marked out
C. left out
D. stood out
牙髓中不含以下哪种细胞
A．未分化间充质细胞B．成釉细胞C．成纤维细胞D．成牙本质细胞E．巨噬细胞
