--Can I have your name, sir?--Err… Albert Johnson, if you _______ know.
The computer system ____ suddenly while he was searching for information on the Internet.
Then came the disappointing news _____ Brazil was beaten by German in the 2010 World Cup, ______ was bound to cast down the Brazilian fans.
American Indians ________ about five percent of the U.S. population .
When I get puzzled about some difficult problems, my teacher always encourages me and says, “Take it _________ .”
After he retired from office, Rogers ________ painting for a while, but soon lost interest.