______ our arriving at the airport, we were given a warm welcome by the local people[ ]

I regret _____ you that Mary was badly injured in theaccident.—I can hardly believe my eyes. She is always socareful.

When she was collecting rubbish in the morning， the cleaner saw a tall man in a black coat______outside the office．

lish class, our teacher often creates anenvironment _____ we are given the opportunity to solve problems ourselves.

Mary noticed ________ with the English way of life.