It’s dangerous to let the children who are ____ walk across the crowded street

We are so sorry for that．We’ll try to determine exactly _________ went wrong that evening．

The Nanjing Yangtze River Bridge is still very strong, ___________it is almost 43 years old.

“Goodbye, then,” she said, without even _____ from her book.

There is a common belief among them _______rubbish can and should be put to good use .