Some scientists believe that is no doubt a cure for AIDS will be found.
A. it; that
B. it; whether
C. there; that
D. there; whether
网友回答
A. it; that
B. it; whether
(答案→)C. there; that
D. there; whether
解析：句意：科学家相信，毫无疑问，艾滋病的治疗方案终将被找到。Believe后面的that引导宾语从句，在从句中第一空用it做形式主语，that引导真正的主语。