【正确答案】正确答案：Move-α rule is a general movement rule accounting for the syntactic behavior of any constituent movement. It goes like this; any element may be moved to another place, or more generally changed in some way, as long as the relevant conditions (principles) are satisfied. That is to say, the movements are constrained by the other modules of grammar in order to rule out ungrammatical forms, such as the kissed boy girl and were kissed the girl by the boy. It is the interaction of move-α with other syntactic principles that results in grammatical strings. It is responsible for the mapping between active and passive.