More and more foreign friends enjoy ________to Peking Opera.
It was not until I came here ____ I realized this place was famous for not only its beauty but also its weather.
--- I am shocked at the news that many pupils were killed in the terrible traffic accident. --- So am I. Little ____ the safety of the poor children.
She showed the visitors around the museum, the construction _____ had taken more than three years.
It suddenly occurred to him _____ he had left his keys in the office.
New technologies have made ______ possible to turn out new products faster and at a lower cost.