纸管内产品的流量()。
A、被电眼检测;
B、依产品本身而定;
C、总是恒定的;
D、被调节阀和浮筒控制。
参考答案:D
All workers, regardless of their sex and education, are required to ______ at the age of 60.
A.resign
B.retire
C.regain
D.retain
脊柱骨折常见的并发症有
A.呼吸系感染
B.泌尿系感染
C.褥疮
D.骨质疏松
E.应激性溃疡