What do you think of this film? – Great! I_______ such a wonderful film before.

While Mary ___ a letter, the children were playing outside.

There’s somebody at the door. Who ____ it be? Is it the postman? — No. It ______ be him. It’s just seven o’clock. It’s too early.

The letter _____ I received from him yesterday is very important. [ ]

It’s not always necessary to look up the words _____ the dictionary while reading. Sometimes we need to guess.[ ]