明确诊断肺血管栓塞症应首选哪项检查

A．动脉血气分析

B．血浆D-二聚体

C．心电图

D．超声心动图

E．螺旋CT

— Why not sit in your own seat, Mary?

I can’t see the blackboard clearly because two tall boys are sitting _____ me.

A．next to

B．beside

C．in front of

D．opposite