aboard, board, alongside ; and, or, butThey were unable to confi

aboard, board, alongside ; and, or, but
They were unable to confirm how many workers had been ______the bus ______how many survived the accident.
【正确答案】：aboard/and
【题目解析】：Aboard通常和指代一种交通工具的名词或特定车辆的名字连用。可以和aboard连用的名词有：bike，boat，bus，coach，ferry，jet，plane，rocket，ship，sledge，space，shuttle，train，truck，yacht等。