Question

【题目】On the third day，I received a message from Mike's wife that she said Mike had been killed in ______ unexplained truck crash on the morning of my call.

Answer 1

【答案】an

【解析】句意：第三天，我收到了来自迈克妻子的短信，她说在我打电话的那天早上迈克在一次不明原因的卡车撞击事故中死亡。此处泛指“一次不明原因的车祸”，故用不定冠词；unexplained以元音音素开头，故填an。