A horrible thought _________ him when he was waiting for Tom in the airport: what if the plane from Malaysia had been hijacked（劫持）?

 I don’t know why he ________ in the middle of a sentence.

 London was ______ to hold the 2012 Olympic Games.

While doubts about the medicine’s safety have____________, interest continues to grow.

The search was________ when night came，even though the child had not been found.