It’s important for us to employ a word or a phrase according to the __________ in language studies.
I felt it a great honour ______ to speak to you.
When you’re learning to drive, _______ a good teacher makes a big difference.
He looked around and caught a man ______ his hand into the pocket of a passenger.
______ their service, the workers of the hotel are active in learning English.
_____ the flies out, we had to shut all the doors and windows.