31. Nobody believed his reason for being absent from the class ______ he had to meet his uncle at the airport.
Some people who don’t like to talk much are not necessarily shy; they _____ just be quiet people.
So sudden _____ that the enemy had no time to escape.
Mary and I see each other ______, but not as often as we used to.
Amy joined a painting group but didn’t seem to _____, so she left.
Sorry, LiMing, I’m afraid I have to ______. Someone is calling me.