Sandstorms in Asia seem in recent years as a result of desertification.
A. to increase
B. to have increased
C. having increased
D. increasing
网友回答
A. to increase
(答案→)B. to have increased
C. having increased
D. increasing
解析：原句意思是，由于沙漠化，近几年亚洲的沙尘暴在增长。不定式、现在分词都可以作表语，表示将来的含义时，一般用不定式。不定式的完成式表示的动作发生在谓语动词表示的动作之前，强调动作的先后顺序。所以选B。