单项选择题
A．支承锚固 B．楔紧锚固 C．握裹锚固 D．组合锚固
A．0.4m B．0.2m C．0.6m D．0.8m
A．(1:0.5)～(1:1) B．(1:0.2)～(1:0.7) C．(1:0.5)～(1:0.7) D．(1:0.2)～(1:0.7)