石膏或夹板外固定之后最应该注意的是（）
A.松脱
B.骨折再移位
C.压迫性溃疡
D.血循环受阻
E.石膏变形
参考答案：D
. It was the hardship _____ he experienced as a young man _____ made him what he is today.
A．that; that
B．that; which
C．which; who
D．that; who
检查火花间隙时，应用（）兆欧表测绝缘电阻。
A.500V
B.1000V
C.1500V
D.2500V
