Abstract A comprehensive study on the accretion and diagenesis of Permian–Triassic boundary microbialites is conducive to a better understanding ecological community after end-Permian mass extinction. Here we studied special microbialite sequences at Tianba section Leye isolated carbonate platform, South China Block. The are shown as small columnar stromatolites, stromatolitic thrombolites, spo...

in the introductory stages of language learning, students are exposed to parative forms explicitly taught in their textbooks. as knoch (2004) mthis is accomplished by teaching the comparative form of the adjective generally directly followed by a than clause. this study aimed to compare between native and nonnative material developers with regard to the coverage of comparative forms. in doing s...