There is a cause-and-effect relationship between the act of testifying and attack and retaliation: the cause is the act of testifying which happens ahead; the consequence is the act of attacking and retaliating which happens behind. 打击报复行为与证人作证行为之间具有因果关系:证人作证行为是原因,发生在前;打击报复行为是结果,发生在后。