Recently, I has have been learning something about nef line bundle,I bundles. I know that when $X$ is projective or Moishezon,a Moishezon, a line bundle $L$ over $X$ is said to be nef iff $L.C=\int_{C}C_{1}(L)\ge 0$ $L.C=\int_{C}c_{1}(L)\ge 0$$for every curve$C$in$X$.Moverover,Demailly had given X$.