Some scientists believe that is no doubt a cure for AIDS will be found.A. it; thatB. it; w

问题补充：

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

答案：

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。