A: We're going to have to postpone the meeting.
甲：我们必须将会议延后举行。
B: Why?
乙：为什么呢？
A: Mr. Chen can't make it today.
甲：陈先生今天赶不来。
类似用语
How come?为什么？
百宝箱
注意“Why?"与“How come?"均表示“为什么？”，但在完整的问句中却有所差异。Why之后必须接倒装句型；而How come之后则接不倒装句型，即“How come+主语+动词？”。
Why is Mary crying?
= How come Mary is crying?
= Why is it that Mary is crying?
= How is it that Mary is crying?
（玛丽为什么在哭呢？）
更多信息请查看口语入门