How____ is the population of the world?  

—Have you ever been to Qufu?—Yes. I went there last year. It’s a very _______ place. 

--What do you think of maths?--My favourite. It’s        for me to study of all the subjects in school.

He must be in the room, because the light in the room is__________. 

—How is the weather in winter in Bejing?—It’s ________.