--Do you know when the Chinese custom from?--Its hard to say. But its characteristics the

问题补充：

--Do you know when the Chinese custom from?

--Its hard to say. But its characteristics the Tang Period.

A. began ; prove

B. started ; show

C. is ; appear

D. dates ; suggest

答案：

A. began ; prove

B. started ; show

C. is ; appear

(答案→)D. dates ; suggest

解析：本题关键是抓住答句中所提供的信息，“Its hard to say’，这表明回答者并不很肯定。而prove证明，show表明，排除A，B。前一空date from意为“追溯至……”