We examine the scenario that the Doppler factor determines the observational differences of blazars. Significantly negative correlations are found between the o
Utilizing a Bz K-selection technique, we obtain 14 550 star-forming galaxies(sB z Ks) and 1763 passive galaxies(p Bz Ks) at z ~ 2 from the K-selected(KAB < 22.5)