位图文件的扩展名是（）。
A.JPG
B.GIF
C.BMP
D.WMF
参考答案：C
允许速度不超过160km/h的线路，曲线地段，未被平衡欠超高，困难情况下应不大于（）。
A.50mm
B.60mm
C.75mm
D.90mm
The border was actually two towns, though no one was big enough to amount to anything.
A. not one B. neither one C. none D. nor
