At the opening________of the school, our headmaster gave a short speech.
With a lot of difficult problems _______, the newly-elected president is having a hard time.
It was unbelievable that the fans waited outside the gym for three hours just ____ a look at the sports stars.
____ into use in April 2000, the hotline was meant for residents reporting water and heating supply breakdowns.
_____ to sunlight for too much time will do harm to one's skin.
He got well-prepared for the job interview, for he couldn’t risk ____ the good opportunity.