The Town Hall ________ in the 1800's was the most distinguished building at that time.[ ]

A. to be completed  

B. having been completed

C. completed  

D. being completed

对进行固定正畸治疗的患者进行口腔健康教育的内容及重点是（）

A.勿咀嚼硬物

B.按时牵引橡皮筋

C.教会患者如何控制菌斑及改变不良习惯

D.定期复诊

E.不要自行拆除牙齿矫治器