refer to不是系动词。The speaker often referred to his notes .那个讲演的人不时地看发言稿。It can also refer to a long-term occupation .它还可指长期的职业。Invariance refers to areas of agreement .不变性指的是一致的部分。The dispute was referred to the united nations .这项争论已提交联合国。The rod is sometimes referred to as a light pipe .这种杆有时称为光管。