The traditional view is _____ we sleep because our brain is “programmed” to make us do so.
The singer hopes her concert will be like a big party ________ everyone enjoys themselves.
The foreigners are ______ by the ________ progress that the Chinese have made.
The summer holidays are not far away _________ we can stay at home and read some good books.
The classroom can ________ 50 students.
Football, ________ is an interesting game, is played all over the world.