XXs或 X's,X级电影, 成人电影(十八岁以下儿童不得观看)XFK心复康XBR=Experimental Breeder Reactor 实验性增殖反应堆XMP=xanthosine monophosphate 黄苷酸, 黄苷一磷酸XDT=Xenon Discharge Tube 氙放电管XOD黄嘌呤氧化酶XRD=X-ray Diffraction X射线衍射xon发送朴通XMT=X-band Microwave Transmitter X 波段微波发射机XMCabbr.一氯代二甲苯 (=Xylene Monochloride)xhfabbr.=extra high frequency 超高频率；extra high frequency 超高调频；超高频率