27. People have become aware ______the fact that carbon dioxide, poison to the environment, contributes_____ air pollution.
| A．of, to | B．/, to | C．of, of | D．of, for |
The bell ________ the end of the period rang _______ our heated discussion .
A indicating , interrupting B indicated, interrupting C indicating , interrupted D indicated, interrupted
Have you read the book _______is broken ?
A cover whose B whose cover C the cover of whose D the cover of that
The time is not far away _____ modern communications will become widespread in China’s vast countryside.
A as B when C until D before
I have many books ,but _____ deals with the problem.
A none of which B none of them C call of which D all of them
The great hall was crowded with many people ,_______many children ________on their parents’ laps.
A including ,seated B including , seating C included , sat D included , sitting