In his lecture, the professor referred to the belief, in contrast to all other countries, ______ the elderly are wise, ______ is particularly dominant (占优势的) in the Chinese culture.
The theory he sticks to ______ to be of no use in our studies.
____ that caused him to serve dinner an hour later than usual.
---- Do you know his address? ---- No, I also wish I _____ where he _____.
—John has put forward _______ most challenging question for us to answer. —Yes, it really is. I have never heard _______ harder one.
Though _____, the news brought them much encouragement.