有一根粗细均匀刻有刻度的竹竿，在左边的刻度3的塑料袋里放入4个棋子，在右边的刻度2的塑料袋里应放入（ ）个棋子才能保证竹竿的平衡．
A：4
B：5
C：6
下列公民在行使权利的是（）
一 Could you tell me ? I must find him.
一Sorry, I'v no idea. But he was here just now.
A lot of things ________ by people to save the little girl now.
根据句意和汉语注释，写出单词的正确形式。
Parents sometimes have difficulty understanding the strange ____ (think) in their children's mind .
