从所给的四个选项中，选择最合适的一个填入问号处，使之呈现一定的规律性：（）
A.A
B.B
C.C
D.D
参考答案：C
He turns a deaf ear to his parents, _____ many times they have pointed out his weaknesses.[ ]
A. whatever
B. whichever
C. however
D. whenever
胫骨干中1/3骨折，容易发生
A．神经损伤B．血管损伤C．骨缺血坏死D．骨折不愈合E．骨筋膜间隔综合征
