Question

I know _________ I promised to take you to dinner, but I won't finish working until ten o’clock.

A．that

B．if

C．what

D．why

Answer 1

A

考查宾语从句的用法。宾语从句结构完整，不缺少疑问信息，排除C、D；主句动词是know，与表示是否的if连用，不合语境B项也排除；因为宾语从句在陈述一件事情，所以用that。