At present there is little doubt short message plays an increasingly important role in ou

问题补充：

At present，there is little doubt short message plays an increasingly important role in our lives．

A. whether

B. if

C. that

D. which

答案：

A. whether

B. if

(答案→)C. that

D. which

解析：考查doubt用法. there is no doubt that否定就用thatthere is doubt whether/if 肯定就用whether/if，说明有疑问,后接同位语从句。Little表达否定意思很少的,故选C.