我国现行印花税实行由纳税人根据税法规定的（）办法。

A.自行计算应纳税额

B.自行购买印花税票

C.自行粘贴并画销印花税票

D.自行申报纳税

E.自行缴纳

Professor Lee's book will show you how you have observed that can be used in other contexts.

A．that you have observed

B．that how you have observed

C．how that you have observed

D．how what you have observed