Is this red bag yours?—No, it isn’t. is that black one.

What would you like to do this Sunday?—–If it doesn’t rain, I _______to Mount Qingyun for a spring field trip.

Never before ________ buying a computer, but now it seems a necessity in my everyday life.

Is this the first time you _____Chengdu ?—-No. But the first time I _____here, the city wasn’t so beautiful.

The Internet is a wonderful discovery,________of great significance to people’s lives.