Nowadays sending e-mails to each other is a way many a student _______ what they think.
He devoted most of his time to his research, believing his hard work would___sooner or later.
China, a country with 145 million elderly people, will remain _______ ageing society during this century, according to _______ Chinese population experts.
--- Shall we walk around the park or go for a bike ride?--- _________. They are both good activities to me .
John plays football __________, if not better than, David.
______ comfortably in his armchair, the old man enjoyed the light music over the radio with his eyes half ______.