--Do you know when the Chinese custom from?
--It's hard to say. But its characteristics the Tang Period.
A. began; prove
B. started; show
C. is; appear
D. dates; suggest
网友回答
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，“It's 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……”