Dual law二元法dualadj.双重的；成双的n.双数dual wavelength laser diode双波长激光二极管dual auto-alternate sweep双自动交替扫描dual wavelength ratiometric双波长比率dual-frequency ultrasonic双频超声dual-channel electrometer双道静电计dual cavity bronchus vessel双腔支气管导管dual-phase microstructure双相组织dual-mode guidance system双模制导系统dually-qualified teachers双师型教师Dual- Teaching Mode Staff双师型师资