【原创】 Vehicles, coal-burning, airborne dust and industrial production ______85 to 90 percent of the major airborne pollution sources in most Chinese cities, the newest research shows.
She has been working hard day and night, which of course, _______ her pale face.
--- Are you satisfied with what he did? --- No. It couldn’t have been ______.
--- He worked out such different questions at a very young age. --- Oh, he ______ a very smart student then.
In our childhood, we were often ______ by Grandma to pay attention to our table manners.
Many lifestyle patterns do such _____ great harm to health that they actually speed up ____ weakening of the human body.