I met an old friend on the train yesterday.[A. by chanceB. on purposeC. in factD. in retu

问题补充：

I met an old friend on the train yesterday.[

A. by chance

B. on purpose

C. in fact

D. in return

答案：

(答案→)A. by chance

B. on purpose

C. in fact

D. in return

解析：考查短语辨析。A 偶然地，无意中 B 故意地 C 事实上 D作为回报地 句意为昨天在火车上我无意中见到了一位老朋友。因此选A 。