ws shocked the public, _______to great concern about students’safety at school.

Ronald Amundsen is considered to be one of the greatest ________ in history because he was the first man to reach the South Pole(南极).

He found _____ impossible to finish so much homework in an hour.

The biggest whale is _______ blue whale, which growsto be about 29 meters long—the height of______ 9-story building.

Great changes have taken place in my home town. It’s no longer ______ it was ten years ago, ______ I spent my childhood there.