Molluscs in the long history of evolution, and gradually evolved to adapt to the environment of the body structure, external structure protection, respiratory, reproductive system, nervous system, circulatory system and excretory system has reached a higher level, to the natural environment in bette

molluscs during their long history in the process of evolution, and gradually evolved into the physical structure to adapt to the environment, external protection construction, respiratory, reproductive system, nervous system, circulatory system and excretion has reached a higher level, to be able t

The mollusk in the long historical evolution process, evolves the adaptation environment gradually the bodily structure, exterior protection structure, the breathing apparatus, the reproductive system, the nervous system, the circulatory system and the excretory system has all achieved a high level,

Mollusca in the long history in the process of evolution, gradually evolved to adapt to the environment of the body structure, external protection structures, reproductive system, nervous system, respiratory organs, circulatory and excretory systems have reached a high level, to better survival in t