下列哪项是骨折早期并发症（）
A.血管神经损伤
B.关节僵硬
C.创伤性关节炎
D.缺血性肌挛缩
E.延迟愈合
参考答案：B
In those days, our________ concern was to provide people who were stopped by the snow storm
with food and health care. [ ]
A. normal
B. constant
C. permanent
D. primary
分程控制回路，控制阀的开、关形式有（）。
A、气开－气开
B、气关－气关
C、气开－气关
D、气关－气开
