下腔静脉受肝癌侵犯和癌栓形成CT表现

A．管腔不规则狭窄

B．完全被肿瘤包绕

C．腔内充盈缺损

D．下腔静脉不显影

E．可以继发奇静脉扩张

Not until ___to do my homework ____ how much time I had wasted playing computer games.

A．I began; I realized

B．I began; did I realize

C．did I begin; I realized

D．did I begin; did I realize