Some researchers believe that there is no doubt a cure for AIDS will be found.
A. which
B. that
C. what
D. whether
网友回答
A. which
(答案→)B. that
C. what
D. whether
解析：考查同位语从句。本题中的同位语从句that a cure for AIDS will be found.解释名词no doubt的内容。That在句中不充当任何成分，只起引导和连接作用。句意：一些研究人员认为，毫无疑问艾滋病的治愈方法将会被发现。故B正确。