单项选择题5月龄公猪,因怀疑患猪肺疫,用头孢噻呋肌内注射治疗3天,疗效欠佳,经实验室诊断为支原体肺炎混合感染巴氏杆菌,进一步治疗应加用的药物是
单项选择题Some large A.Cmotors are equipped with heatersThese could be _____(1) resistance heaters bolted directly to the framE.;(2) low voltage windings embedded in the motor windings