溃疡性结肠炎()
A.X线钡剂灌肠示结肠呈铅管征
B.X线钡剂灌肠示回盲部钡影跳跃
C.X线钡剂灌肠示盲肠充盈缺损、肠腔狭窄
D.X线钡剂灌肠示回肠末端线样征
参考答案:A
There are many trees on ____ sides of the river. [ ]
A. any
B. either
C. both
D. neither
简述无土栽培营养液对水质的要求。