Beijing is famous ____ its places of interest. [ ]
A. for
B. as
C. to
D. in
答案:A
下列关于金属烤瓷冠基底冠的描述,哪一项是错误的
A.有足够的厚度和强度支持瓷层B.与牙体适合性好C.金瓷衔接处避开咬合接触区D.金瓷衔接处为刃状E.唇面应该为瓷层留出0.85~1.2mm的间隙
试述纱线强力与断头的关系。