答案:C
当电压下降到额定电压()时,应使电动机停转。
A.75%~90%
B.35%~70%
C.20%~35%
D.85%~95%
贲门周围血管离断术,结扎、切断高位食管支至贲门上方()
A.2~3cm
B.4~6cm
C.3~4cm
D.1~2cm
E.6~8cm