问题补充：
Unluckily, when I dropped in, Dr. Smith , so we only had time for a few words.
A. was just leaving
B. has just left
C. had just left
D. just left
答案：
(答案→)A. was just leaving
B. has just left
C. had just left
D. just left
解析：考查时态。句意：不幸地是，当我来的时候，斯密斯博士正要出去，所以我们只有时间说了几句话。根据句意可知他还没有离开，但是正要离开，故使用过去进行时表示过去将来时。故A正确。
