The United States of America___one of the most developed countries in the world.

The Olympic Games ____ held every ____ years.

A chemical works____ built there.

Chairman Mao' s works ____ published.

The Arabian Nights ____ well known to the English.

The number of deer, mountain lions and wild roses ____ much if people leave things as they are.

A large number of students in our class____ girls.

There ____ a pen, two pencils and three books on the desk.

The great writer and professor____.

The League secretary and the monitor____ asked to attend the .meeting this afternoon.