If I can help_______, I don't like working late into the night.

A. so       B. that     C. it      D. them

上题中it如何解释？

解释：

上题为2006年全国高考试题。题目中 it 代替I don't like working late into the night。句意为：如果能不工作到深夜，我是不喜欢工作到深夜的。例如：

They never go there if they can help it.如果能不去那儿的话，他们是绝对不去的。(麦克米伦高阶英汉双解词典)

（not if he/she/I etc can help it: used for saying that someone is trying to avoid something they do not like doing如果能不……的话，他/她/我等就避免(做某事）)