Mr Liu is ____ unusual teacher. He has written _____ useful book for his students.

Nothing wrong with it, ______?—No. Yours is a specially-built model. Drive carefully, though.

The train____at 6 o’clock tomorrow morning so I’ll have to get up really early.

Let’s buy the blue car. It’s than the yellow one and it’s more beautiful.

How many trees are there on topof the mountain? _________