It_____ have been Tom that parked the car here, as he is the only one with a car.

--- This must be a footprint of a tiger. --- It ____ be. A tiger’s should be much larger and deeper than this. 

---Who is the tallest boy?      ---It ______ be John.. John is of medium height.

 .Susan’s parents have bought a large house with a swimming pool. It ______be very expensive.

—A medical team was sent to Japan by air five hours ago.—So they ______________ have arrived by now. The flight usually takes four hours or so.