How did all these ( ) A.came out B.come u

问题描述:

How did all these ( ) A.came out B.come u
How did all these ( )
A.came out
B.come up
C.come across
D.come about
请说明理由.

come about发生 come out出现 come arcoss偶遇come up上升,发芽那答案是什么!!A这句话的意思是什么这些是怎么发生的