诊断结肠病变，应首选（）
A.单对比灌肠检验
B.CT
C.气钡双对比灌肠检查
D.立位腹平片
E.卧位腹平片
参考答案：C
如果一个人站在南极点上，那么他的前后左右均是
A．东
B．南
C．西
D．北
The WTO cannot live up to its name ______ it does not include a country that is home to
one fifth of mankind. [ ]
A. as long as
B. while
C. if
D. even though
