If you are ________about Australian cities,just read the book written by Dr. Johnson.
Eating too much fat can _______ heart disease and cause high blood pressure.
--- Tom, why didn’t you come to the meeting yesterday? --- I _____, but my car broke down.
There is no doubt ______ man will conquer nature some day.
______ different life today is from ____ it was 20 years ago.
Paper-making began in China and from here it ________ to North Africa and Europe.