6.Bilateralsymmetry The arrangement of parts in fan organism in such a way that the structure can only be divided into similar halves (mirror images) along one plane.
7.For objects with bilateralsymmetry, those with one plane of symmetry, such as most animals (humans included) and many machines, the above method implies modelling one half of the object, and then mirroring a duplicate of the first half to get the whole object.
8.As we all know, Bilateralsymmetry, three-layer embryo, metamerism and having a relatively developed head are the common characteristics of the Arthropoda and Annelida, So it is believed that arthropod originated from annelid.
10.On VR images,the vocal process and muscular process were demostrated in a rate of 53.6% and 60.7%,and the symmetry of bilateral CAJ was revealed in 27 cases.