Henry _____be at home because he phoned me from his office just now.

—How many students are there in your school?—      the students in our school      over two thousand. 

—Someone is knocking at the door. Is it Ann?—It _____ be her. She is giving a performance at the theatre now.

My sister met him in the hospital yesterday afternoon, so he _________ your lecture.

The dictionary ________ me more than 100 yuan.