It was lucky that little J...

答案C

答案解析试题分析：

句意：很幸运小杰克在火灾爆发的时候不在家，否则他就会丧生了。这里的otherwise相当于一个虚拟条件句If

little

Jack

had

been

at

home

when

the

fire

broke

out，可知是和过去情况相反，所以主句是would

have

done，选C。

考点：考查虚拟语气