_______ that the scientist will give us a talk next month?
B
it在句中作形式主语，that引导的从句是真正的主语。本句运用的是疑问句式。
After I _________ a letter I took her to a __________ ________.
A well-known example of the large scale destruction of an ecosystem through vegetation removal to accommodate tourist facilities is the case of the _______.
I ’ve got the order from the boss that the work _______ finished before 5 p.m. today.
A man flown to a time zone different by 10 hours will ________ eight days to readjust his palm sweat.