D说下理由吧1.A.中 what made matters worse是插入语，不能写为主语从句式的主从复合句，正确的为：,and what made matters worse， night began to fall.2.B.中what was worse,缺少make是不能构成插入语的，改为：what made matters worse, it was getting dark.3.C中to make matters worse that night was falling作为插入语的部分应该用逗号独立出来，改为：to make matters worse, night was falling4.D中worse still,可以作为插入语使用，并有逗号和后面的句子night had fallen分割开来，正确5.他们当时在森林里迷了路，并且更为糟糕的是，夜幕已经落下了。不懂再问哦，祝你学习进步！