The chairman thought _________ necessary to invite Professor Smith to speak at the meeting.
It's everybody's desire that every effort___________to reduce the pollution in our city.
Mary waited for a reply, but__________came.
Mo Yan's winning of 2012 Nobel Prize shows the world's________of China" contemporary literature.
-You seem to be familiar with this city.-I_______here for three years. It's great to be back.
The air quality in our city, _____is shown in the report, has improved a lot recently.