We all think it is Jack as well as his wife that______ for their son’s bad manners in public.

A．are to blame

B．is to be blamed

C．are to be blamed

D．is to blame

不属于玻璃离子水门汀优点的项为（）。

A.在口腔环境中无溶解

B.可以释放氟化物

C.与牙齿有化学粘结

D.对牙髓刺激性小

E.可用于乳牙修复