彩色多普勒成像时不影响帧频的因素是

A．角度大小

B．深度

C．探头频率

D．滤波器

E．脉冲重复频率

No sooner ____ to the cinema ____ the film began. [ ]

A. had he got, than

B. he had got, when

C. did he get, than

D. had he got, when