— How long do you think it is _____ he took up the job? 

— Half a year at least. [ ]

A. when

B. before

C. that

D. since

关于腹水浓缩回输下列哪项说法有误

A．多用于难治性腹水治疗

B．其原理是将腹水蒸发浓缩

C．能提高血浆白蛋白浓度

D．能改善肾血液循环

E．副作用是易致电解质紊乱