用方框中所给单词的适当形式填空，每词仅用一次，每空一词。

could  wide  except  die  safe

 
Internet is ________ used in the world.
When we found the poor dog, it was already _______.
He didn’t receive any presents ________ a box.
He was serious about the _______ of the children.
It ______ be Frank’s schoolbag. He lost one this afternoon.