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：考察固定句型。Be doing sth when…正在做某事在这时…(意料之外的事情)；句意：在一个星期五，我们正在收拾书包准备去度周末在这时我的女儿听见了喊救命的声音。