Please check the list carefully ________________ make mistakes.
Great changes have taken place in that school. It’s no longer ___ it was 20 years ago, ____ it was so poor.
Dark clouds _______ the sunlight. It seemed as if it was going to rain.
The little child didn’t understand the ____ question so there was a ____ expression on his face.
Robert is interested in ________ astronomy and he wishes he could make a trip into ________ space one day.
----Would you permit me ______ here?---- Sorry. We don’t permit ______ here in the reading room.A. smoking, smoking B to smoke, to smokeC. smoking, to smoke D. to smoke; smoking