Modal verbs for speculation and deduction

This............ be the flag of Bulgaria because its colors are white, green and red.

• must

• could

• may

• can't

Maria.............be at home. The lights are on.

• must

• can't

• might

• may

This car ............be Tom's. His car isn't white.

• may

• could

• can't

• must

Martin ...............have sent the letter. it isn't on his desk.

• can't

• might

• may

• must

Serious historians say thestory ..................be true.

• must

• can't

• might

• may

Some people think it ....................be true because there are a lot of miserious facts.

• may

• can't

• must

This story ..................have happened but we are not sure.

• can't

• must

• could

Some ministers ..................have known the secret.

• might

• can't

• must

Her parents ...................have live a healthy way of life. Some days ago they turned 94.

• may

• can't

• must

Kate's brother ................ have studied at a university. He works as a plumber.

• can't

• must

• might

• may not