How long do you suppose ______ we applied for the job ________ we had been trained .
Several new railways are under _____ in China .
The traffic is heavy these days . I _____ arrive a bit late , so could you save me a place?
John is fond ____ football, while his brother is crazy ____ music.
–Ann is in hospital. ---Oh, really? I _____ know ,I ____ go and visit her.
It’s important for students to employ a word or a phrase according to the _____ in the language we study .