from 544 million to about 500 million years ago; marine invertebrates
cambrian period 例句
英汉例句
the basement strata and the migmatite, however, were formed much later, about cambrian period and early palaeozoic era.
但其基底地层和混合巖形成时代较晚,为寒武纪和下古生代。
afterward, global large-scale massive volcanic activity in permian period generally brought about metamorphism whole middle cambrian period volcanic sediment rock in research area.