急流常常穿过什么类型的锋面系统？（）
A.暖锋和冷锋
B.暖锋
C.锢囚锋
参考答案：C
The names of the currencies of U. S. A. U. K and Germany are called ______ respectively.
A．US Dollar, Pound Sterling and Deutsche Mark
B．US Dollar, Deutsche Mark and Pound Sterling
C．US Dollar, Guilder and Deutsche Mark
D．US Yuen, Pound Sterling and Deutsche Mark
电缆金属外皮可作零线。（）
