abbr. 柴油净化系统(Diesel Particulate active Reduction system);拨号脉冲接收机(Dial Pulse Receiver) r and d: R and D,R & D =research and development 研究与发展。 the s (p, d, f) orbital s(p,d,f): 轨道constant p-r interval: 恒定的p-r间期depression of p-r segment: p-r段压低long r-p tachycardia: 长r-p心动过速下载手机词典可随时随地查词查翻译