There have been several new events _____ to the program for the 2008 Beijing Olympic Games.
You can't get to the island __________ by boat.
At the meeting they discussed three different __________ to the study of mathematics.
________ to his experiment, he didn't notice that autumn had already come.
In a __________ state, the children had a meeting and decided to choose one person to ask for more food.
Though __________, he still earned a lot of money to support his family.