问题补充：
--- Believe it or not, I an old friend of mine while abroad.
--- Oh, it’s a small world.
A. came up
B. came out
C. came across
D. came about
答案：
A. came up
B. came out
(答案→)C. came across
D. came about
解析：本题考查的是词组的含义辨析。四个词组中，come up一般与with搭配，表示的是“想出、找出（答案等）”；come out表示“出版”或“结果是（类似于turn out）”；come across表示“偶然遇见”，同义词有run across等；come about表示“发生”。根据句意，我在国外偶然遇见一位老友，由此可知答案为C
