— What does " No parking " mean?

— It means _____________. [ ]

A. We can park our bikes here.

B. We can't park our bikes here.

C. We can't ride our bikes here.

患者女，27岁，上前牙牙龈反复出现瘘管1年，经多次搔刮及烧灼瘘管无明显好转。查体见烤瓷全冠修复，唇侧龈方见针尖大小脓点，略红肿，X线片显示根管内冠1／3铸造桩影像，根尖3mm欠充填，根尖区见阴影

引起根尖炎症的优势细菌（）

A.变形链球菌

B.乳酸杆菌

C.牙龈卟啉单孢菌

D.放线菌

E.以上皆正确