___ himself in carrying out an experiment, he can’t spare time to look after his children.

A．Occupied

B．Having occupied

C．Occupying

D．Having been occupied

胎儿淋巴囊肿的临床的声像图表现，下列哪项不正确：

A．发生在颈部的约占80％

B．是由于淋巴系统梗阻致

C．囊壁菲薄

D．无回声区在胎儿皮下组织向外扩展

E．囊壁上可见较丰富的血流