呈舌状、快状、鱼鳞状嵌在型钢表面上的缺陷称为（）。
参考答案：结疤
As Jack left his membership card at home, he wasn't allowed into the sports club.
A．going
B．to go
C．go
D．gone
容易发生骨折的面骨是( )
A．颧骨B．蝶骨C．下颌骨D．上颌骨E．以上均不正确
