—The river smells so terrible! How did it come about?—People used to pour dirty water into it.
It’s two and a half weeks since the exchange students __________ Wuxi.
Little Tom has got a lot of birthday presents, but he isn’t able to take all of them ___.
We can have ___ blue sky if we create ___ less polluted world.
-----Did you notice him come in? -----No. I _____ a football game.
You should return the digital camera to Sally ________she will get angry.