改错题
Most of animals communicate with one another to a greater or lesser de- 【M1】______ gree, and the more social a species, the more communicative it intends to be. 【M2】______ Communication comes in many forms—it may be acoustic, visual, chemical or tactile and, depending upon the message and the medium, different types of communication may be more or less effective and/ or efficient. A species may excel at one type of communication and therefore be almost ""blind"" in 【M3】______ another. For example, humans use a very advanced form of acoustic com munication, language, and yet our olfactory communication is extremely poor compared to most other mammals. While there aren't any species that can compete for human language in 【M4】______ terms of their richness and complexity, some species have relatively large 【M5】______ vocal repertoires and extended communication networks. Elephants are one 【M6】______ such species. Elephants also communicate with one another using intricate chemical and tactile signals and visual displays. If we have to rank these 【M7】______ different systems in order of importance to elephants we would put acous tic and chemical communication together as most important, followed by visual and tactile communication. But we are not elephants! So, why have elephants evolved such large vocal repertoire and such an extensive commu- 【M8】______ nication network? One answer is that elephants have a very complex social system and, therefore, they have needed to develop a complex suite of vo calizations to interact in an appropriate way to the many different individu- 【M9】______ als they meet on a daily basis and to mediate many complex relationships 【M10】______ that they maintain.