___ you succeed, you ___ many hours.
Often,even a common thing of the past can ________ the image of life in the ancient time.
According to an old story, Leif followed Biarni’s directions and sailed to _______ is believed to be the coast of present-day Canada.
While he was at college,he took part in political activities,and was thrown into prison.
Great changes have taken place in China since the People’s Republic of China in 1949.
At night we can see stars in the universe.