关于输精管的叙述,下列哪项不对()
A.为一个肌性管道
B.是构成精索的主要结构
C.起自附睾尾
D.管腔较细,管壁较薄
E.末段膨大形成输精管壶腹
参考答案:D
He told me that by the end of this year they______together for twenty years.
A.would work
B.had been working
C.will have worked
D.would have been working
超声的生物学效应的叙述,错误的是()
A.声功率单位是W/cm2
B.产科胎儿IOB<20mW/cm2
C.声强是单位面积上的声功率
D.探头发射超声脉冲时将电能转换为声能
E.声功率是单位时间内超声探头发出的声功