---Is Mr Hu in the reading room?---No, he _______be there. He has gone to Tianjin.
I knocked on the door but ________ answered.
— ________ did you put my glasses just now, Bill? —On the desk.
Tom was ill yesterday, ________ he didn’t go to school. But he’s better now.
We usually read English ________ the morning.
Kate and Alice are good friends. ________ often help each other.