问题补充:
It’s reported that a plane with five people crashed into the mountain several days ago.
A. on board
B. on the board
C. in board
D. in the board
答案:
(答案→)A. on board
B. on the board
C. in board
D. in the board
解析:on board意为“在船上、在飞机上”,为固定的介词短语。没有B、C、D这样的搭配。