－How about the pollution in the countryside?－Luckily, it’s not as serious as _______ in the big cities.

This is _______ MP4. Yours is over there.  

------- Gina , isn’t this book   ________ ?----- Yes , it used to belong to    ____  , but from now on it isn’t .

—Is your ipad white, Mandy? —No, it isn’t. _______ is black.

Which of  the two cameras are you going to buy?—I’ll buy      of them，so I can give one to my friend．