It’s well known that good relationship between two countries __________ the development of mutual culture and economy.
Being exposed to loud music too much ________ caused hearing loss in some teenagers.
Peter was so excited _________ he received an invitation from his friend to visit Chongqing.
The international agreement, __________to help people kick off the habit of smoking, was signed two years ago.
The fact has worried the people across the world ___________ the earth is becoming warmer and warmer these years.
Bob would have helped us yesterday, but he ____________.