Only when I left my hometown ________ how precious it is to me. [ ]

A. did I realize  

B. I realized

C. had I realized  

D. I had realized

良性叶状囊性肉瘤的声像图特点是

A.肿瘤边界清楚、完整、光滑 

B.内部呈细点状回声，分布均匀，或为无回声区 

C.后方回声增强 

D.肿瘤巨大时，可呈囊状或分叶状 

E.以上都是