Doctors advise us ________masks on such hazy days.
--What do you think of the EXPO 2010? --- It’s great, of course. people are going to Shanghai for the EXPO 2010.
---Do you know Lisa’s address? ---No, she didn't tell me ________________.
---You are quite different from your sister. ---Yes. We are both short. But my eyes are ________ than ________.
---The sick kids look unhappy. What shall we do? --- Let's do something to ___________.
— Could you tell me _____ yesterday? —The Great Wall.