The shop stayed ________ till six o'clock.
For years scientists have been worried about the ______ of air pollution on the earth's natural conditions.
Don’t be angry with us. We ____ with you together, but we were busy with our final reports when you called in.
With the progress of the society, women all over the world have improved their social ______ and rights.
It wasn’t until near the end of the letter ______ she mentioned her own plan.
The lift in that tall building went wrong and got trapped ______ the floors. People in it had no way out and were in panic.