校正原料一般分为（）校正原料，（）校正原料，（）校正原料。
参考答案：铁质，硅质，铝质
-David has made great progress recently.
-______, and ______.
A． So he has; so you have
B． So he has; so have you
C． So has he; so have you
D． So has he; so you have
托马斯征阳性常提示为：（）
A.髋关节脱位
B.髋关节结核
C.髂胫束挛缩
D.股骨颈骨折
E.小儿麻痹后遗症
