The painting you drew is beautiful. But why not paint the walls ________ .
Nowadays it’s very useful ______ a foreign language.
His English is as ______ as his Chinese.
— Did you see the film last night? — No, I ______ some shopping at that time.
— Do you want to play another game of cards? — I’d like to, but it’s getting late. I really ______ go.
Some students are doing their homework in the classroom while ______ are reading.