Where is Jack? —He _________ basketball on the playground.

Listen! Is Kitty in the next room? —- No, it ______ be Kitty. She has gone to Beijing.

Using many symbols makes ______ to put much information on a single map.

Whose French book is it?– It __________ be Lucy’s. Look! Her name is on the book!

_____ did your uncle leave his hometown?—He ________ for nearly twenty years.