In the past month, cruel snowstorms hit some European countries and America , great transportation problems in these countries.
A. causing
B. caused
C. to cause
D. having caused
网友回答
(答案→)A. causing
B. caused
C. to cause
D. having caused
解析：考查非谓语动词。causing great transportation problems in these countries在句中作结果状语从句，选A。