Have you ever comehere before?-No, it is the first time that I_ to this city. [ ]

ys, many people walk to work ________Copenhagen Conference calling for living a low-carbon lifestyle to deal withglobal warming.

ave you seen my U-Disk—____________ you bought last Sunday I’m afraid Ihaven’t seen ________.

Housing prices in Beijing and Shanghai are now largelyfor low-income families,

The computer was used in teaching. As a result，not only _____，but students becamemore interested in the lessons.