________ students are required to take part in the boat race.
Mike’s never willing to change any of his opinions. It’s no use ______ with him.
The organization was founded (建立) for the ________ of poor children .
People try to save time by using their own cars, and this ________ creates further problems.
I was about to leave_______ something happened, which attracted my attention.
Our city has experienced _______ this year as it did last year.