3.EG Cancri is a CVs that has large - amplitude outburst (7mag), slowdecline from outburst, long intervals between outburst and short period. From above properties, we classify the CVs, EG Cancri, as a WZ Sge type DN is plausible.
4.When the lake is deep,the long-term slowdecline of lake level will certainly lead to gradual increase in δ18Oc,but the long-term rising of lake level can also accompany the gradual enrichment of δ18Oc.