So far we have done a lot to build a lowcarbon economy, but it is _____ideal. We have to work still harder.[ ]

A. next to  

B. far from

C. out of 

D. due to

外伤性心包填塞最可靠的诊断方法是（）。

A.外伤史

B.心包穿刺抽出多量血液

C.呼吸困难

D.X线透视心脏搏动弱