---What were you doing when the UFO ?
---I a milk shake.
A. reached, made
B. reached, was making
C. arrived, made
D. arrived, was making
网友回答
A. reached, made
B. reached, was making
C. arrived, made
(答案→)D. arrived, was making
解析：考查词汇和时态。句意：----当不明飞行物到达的时候，你在做什么？---我正在制作一杯奶昔。故选D。