Low-carbon lifestyle is of great benefit to improve the world environment._________can be enjoyed from it until you have a deep understanding of it,however.
______ on the portrait, mother was deep in thought.
Seeing the sun _____ above the surface of the sea we let out a shout of joy.
The news sounds _______.
Speech is ______ heard when it is given in a clear voice just slightly louder than normal.
-----When will they come back? -----I _____ don’t know.