用四妙勇安汤治疗血栓闭塞性脉管炎，其证型是（）。

A.寒湿阻络

B.血瘀气滞

C.湿热毒盛

D.气血两虚

E.肝肾阴虚

During  the reconstruction of  the city, many modern tall buildings went up ____ old  shabby houses

were torn down.     [ ]

A. where    

B. in what    

C. in which    

D. which