---         is it from your home to your school?

---It is about twenty minutes by bike.

A．How far

B．How long

C．How many

D．How much

引起双侧声带麻痹的最常见原因是（）。

A.颈部肿瘤

B.肺肿瘤

C.甲状腺全切术

D.喉外伤

E.中枢神经疾患