Look at the black hat. It must belong to Mrs. King.—No, it _____ be hers. I saw an old man put it here just now.

Have you thought of the topic for the composition? — Not yet．I _____ it very carefully, but I haven’t decided

We all feel puzzled why the students _____ the same mistakes repeatedly in exams

This book is said to be a special one which ________ many events not found in other history books. [ ]

Where did you go on holiday this summer America — You are ______. We went on a 10-day-tour in Canada.