∵ab=cd=23,
∴a+cb+d=2+23+3=23.
The children are _____________ the Christmas tree. [ ]
A. putting on
B. putting
C. putting up
骨迷路因局灶性吸收并被富含血管和细胞的海绵状新骨所替代,继而血管减少,骨质沉着,形成骨质硬化病灶而产生的疾病,称为()
A.听神经瘤
B.梅尼埃病
C.耳硬化症
D.迷路炎
E.以上均不对