Alice was ill, so her mother________ her at home.
-Look, your sister is playing the piano over there.-She ______ be my sister. She has gone to America.
It is polite ______ you to give seats to the elderly.
-Why are there a lot of dead fish in the river?-Because they were ______ by the polluted water.
- Thank you so much for the gift.-_______.
_______ points you get, _______ levels you’ll go to.