As is known to all language learners, the newly learnt words will soon be forgotten unless ______ used in everyday communication.
It was ten years ago ______ we last met in our hometown.
---- Mike, you clean the windows of the classroom this afternoon,_______? ---- But I cleaned them only yesterday.
The young man who we talked a lot about yesterday is unfit for the work, _____?
---- You have never seen an American film, have you? ---- ________. How I wish I had such a chance!
________ if you want to do something, or you won’t be able to do it well.