My friend Bob just bought an apartment in a suburb of Beijing last week, which is much smaller than ours but is three times________expensive.[ ]

A. very  

B. so

C. too  

D. as

使用磁共振成像对比剂合并哪项技术最有利于病灶的显示

A．呼吸门控技术

B．心电门控技术

C．预饱和技术

D．梯度运动相位重聚技术

E．脂肪抑制技术