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.