The chairman thought ______ necessary to invite Professor Smith to speak at the meeting.
At present , many people from the countryside go to the cities ______better jobs.
What the doctors really doubt is ____my mother will recover from the serious disease soon .
--I like Tom very much _____he sometimes gives me some trouble.-- Oh, it’s unbelievable.
Our English teacher advises us ____________ more after class.
— How was your weekend?— Great! We ______ a picnic by the lake.