Quarter Horse Directory四马目录 Quadruple High-Definition (3840 x 2160 pixels)(四3840高像素×2160) Quarter High-Definition (640 x 360 pixels)节(640×360度高像素) Quantum Hadrodynamics (nuclear physics)量子Hadrodynamics(核子物理学) Quantum Hydro- DdynamicDdynamic量子水力 QSound High Definition audio libraryQSound高清音频的图书馆