In our class, the student leaders are on ______ duty every ______ few days.
It is ______ great honor for every country to host ______ Olympic Games.
If a television or radio breaks the new rules, it is forbidden to screen advertisements and the officials ______ face serious punishment.
There is no need to add in trees to create shade because many town and city gardens are __________ shaded by buildings.
One of the great things about science is that it has taught us to be __________ about surface appearances. The world seems flat, but it is, in fact, round.
Decision-makers will take a __________ approach to opening new stores as the global economy slows down.