Don't handle the vase as if it ____ made of steel. [ ]

A. is

B. were

C. has been

D. had been

一位古董商要出售以下文物：有铭文的青铜器、楷书书写的《道德经》、行书书写的关汉卿《窦娥冤》、隶书刻写的竹简。他最可能是何时何地的商人（）

A.明初的南京

B.东汉的洛阳

C.北宋的东京

D.唐末的长安