After his retirement, John fishing as one of his new hobbies.
Mr.Wang ______ the person referred to at the meeting be put in prison.
It is well known to all that water, ______ enough, can change into ice quickly.
I would love ______ to the party that evening, but I had an unexpected visitor.
Thomas _____ in inventing many electrical machines
The Changjiang River has been polluted badly and is not good _______.