LTE的下行空口速率能够获得巨大提升,主要是因为采用了()技术和()技术。
参考答案:OFDMA、MIMO
非均匀性脂肪肝的超声造影表现是()
A.动脉期或门脉早期病灶周边结节样或环形增强,后呈向心性充填
B.动脉早期由中央向周边离心性"轮辐状"增强,门脉期持续增强
C.在造影过程中无增强表现,呈边界清晰的三期无回声结节
D.动脉早期瘤体完全增强,门脉期及延迟期呈低回声,"快进快出"
E.超声造影增强与周围肝组织表现一致,难以区分病变部位
They felt so _____ that they _____ go to bed early.[ ]
A. excited; could
B. excitedly; could
C. excited; couldn't
D. excitedly; couldn't