He was left alone, with ________ to look after him．
A.someoneB.anyoneC.not oneD.no one在线课程D
这句句子的意思是“他被一个人留下。没有人照看他。”从含义上讲，只有选项C和D正确，但not one后需跟可数名词，而no one可以单独做成分。