One Friday, we were packing to leave for a weekend away my daughter heard cries for help.
A. after
B. while
C. since
D. when
网友回答
A. after
B. while
C. since
(答案→)D. when
解析：考查连词：一个星期五，当我们正在收拾行装准备外出过周末时，我女儿突然听见求救声。当一个可延续动作（packing）发生时，另一个动作突然发生。表示时间的when后面跟不延续性动词(heard)。While后面接连续性动词。Since自从，after在…后面。选D。