I visited many places ______ my trip to France. [ ]
A. in
B. at
C. for
D. on
答案:D
下列物质中不能与费林试剂反应的是( )。
A.乙醛
B.苯甲酮
C.甲醛
D.异丁醛
正常成年人股骨颈颈干角平均为()
A.120°
B.125°
C.127°
D.130°
E.140°