He allowed me ____ the experiment.

Since her only child passed away a few years ago, family has been a ________ topic for her.

The judges gave no hint of what they thought, so I left the room really ________.

During the opening ceremony, “Miss Smile” has won the hearts of Chinese Internet users after being caught _____ the same smile for nearly 20 minutes．

There is a piece of news from Shandong Province saying: ______in the school-bus for the whole day, the child died for lack of air.