With a lot of difficult problems _______, the newly-elected president is having a hard time.
In the U.S, ______a tip is thought to be polite when paying the bill.
He is the only one of those clerks ________ to the important conference.
When I turned to Tony for help, I found that the more he tried to explain, ___________.
The two boys share the same hobbies but they are quite different _______ personality.
It won’t be a very long time _________ he is in business for himself.