单项选择题 At the conference，people of different（）were given a chance to exchange theirs with each other.

单项选择题 It was foolish of him to（）his notes during that important test, and as a result, he got punished.

单项选择题 As everyone knows，the South China Sea is（）part of China，（）important part of China，any other country outside Asia doesn’t have（）say in this issue.