Take a map of New York with you while traveling ________ you have a guide or know the city well.
The maths problem is so difficult that none of them can .
The foreigners have been in Beijing for three years, so they are familiar the city .
We should try our best English well.
We shouldstudents computer games.
– These tickets are useless. Can I ? --Yes, but make sure you put them in the dustbin.