-I didn't go to the art show, because I lost my ticket.-You______have borrowed mine I didn't go to see it anyway
---- Could I have a word with you? ---- Sorry, I am busy ______. Shall we do it later?
---Why didn’t you go to yesterday’s meeting? ---I would have but I ______ too busy working on the important experiment.
According to the rules, students must not ____ their books during examinations.
The summer is already here, and it _____ to be a most severe one.
The bad weather meant__________ the rocket launch(发射)for 48 hours,.