In his lecture, the professor referred to the belief, in contrast to all other countries, ______the elderly are wise, ______is particularly dominant in the Chinese culture．

It is known to all that every minute ____ full use of____ the lessons will benefit students a great deal．

The two sportsmen congratulated each other________winning the match by shaking hands.

There is no doubt ______ he did is good for us.

______ is no need for primary students to work at their desks all the long.