We should be explicit _______ the functions and benefits of the Internet, one of which is that we can also correspond _______ people in distant places.
As he reached _____ front door, Jack saw _____ strange sight.
_______ that he was in great danger, Eric walked deeper into the forest.
_____twice, the postman refused to deliver our letters unless we chained our dog.
We are invited to a party______ in our club next Friday.
Tony was very unhappy for ______ to the party.