Traveling around big cities by taxi can cost a lot of money, but it’s usually to take the underground train to most places.

Let’s look at pictures ______ Beijing Opera. [ ]

I can’t remember when exactly she left ________city. I only remember it was ________Sunday

Open the window, please. —Certainly. Which one? _____ beside the door?

On summer nights, we often go to sleep ____ the window open.[ ]