在光滑的地面上放着用绳子连接的物体A、B和C,力F作用在C上（如图2）.

在光滑的地面上放着用绳子连接的物体A、B和C,力F作用在C上（如图2）.
问那一对是平衡力?哪一对相互作用力?
（1）、A对B的拉力和B对C的拉力.
（2）、B对A的拉力和A对B的拉力.
（3）、A对B的拉力和C对B的拉力.
（4）、B对C的拉力和C对B的拉力.

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