As the sky lightened even more, they began to ______ their surroundings more clearly.
 
【正确答案】 D
【答案解析】 动词词组辨析。fall out“争吵,闹翻”;fall into“落入,陷于”;make up“编造”;make out“辨认出,拼凑”。make out their surroundings more clearly更为清楚地认识到他们的处境。故答案为D。