Are these your sheep ?—No. Mine _____ on grass at the foot of the hill.

an be seen in the chart right here, theair pollution level in the city has been increasing over the last months

If you come，you must be prepared to keep moving，______ it is too cold to stand and watch for long.[ ]

The old factory has been ____to make way for a supermarket. [ ]

Everyone in my class _________ his lessons.