同意黎老师的分析！turn to sb 的意思是“求助于某人”，turn to sb for sth 的意思是“求助某人得到某物”。在 Without someone to turn to for advice, making the most appropriatechoice can be difficult. 一句中，Without someone to turn to for advice 为 without 引出的复合结构。句子大意为：Withoutsomeone to turn to for advice,making the most appropriate choice can be difficult. 在没有人可以征求意见的情况下，要作出最恰当的选择有时会很困难。