My grandparents like to live in a house is not very big but bright and comfortabe.A. which B. who C. what
—It smells terrible. What has happened here?—Look, there is much waste gas _____ from the chemical factory.
—Have you finished your homework?—Not _____. There are still some exercises to be done.
_____ the environment is important for human beings.
This is the most beautiful park I have _____ visited.
Xi’an is a city with many places of interest and __ tourists come here every year.