My brother is ____ years old．Today is his _____ birthday．

Do you know why Anna hasn’t come to school today? —I’m not sure. She _______ be ill.

All he wanted was to go abroad for _______ education.

It is said that the gravity on Mars is only aboutof the gravity on earth.

Who is ___ English teacher?—Well, it’s Mrs. Green. She teaches ____ English very well.