We have to admit that never in the past twenty years ________ so greatly as before.[ ]

A. did the city change  

B. the city has changed

C. has the city changed  

D. the city had changed

青年工人，体重60kg，烧伤后半小时急诊入院，烧伤面积Ⅰ度10％，浅Ⅱ度20％，深Ⅱ度30％，Ⅲ度20％。

首先要预防和治疗的是（）

A.急性呼吸衰竭

B.急性肾功能衰竭

C.curling溃疡

D.低血容量性休克

E.全身感染