骨软骨瘤肉眼的3层结构是（）、（）和（）。
参考答案：软骨膜；软骨帽；肿瘤的主体
_____ with the problem of heavy traffic, more and more people prefer to take buses rather than drive
cars. [ ]
A. Face
B. Faced
C. Facing
D. To face
