The total sedimentation was that rivers were branching and migrating frequently,and the sedimentary structures and fossil of ichnite were growing generally.
Methods Sputum culture for Mycobacterium tuberculosis and its L forms was conducted from both silicotuberculosis and silicosis groups, and the results were compared.
Superpopulation model is a bridge between survey sampling and other branches of statistics.It is helpful to study sampling theory with the tool of superpopulation models.