上文讲到这种荷尔蒙能够激发一种群居本能,the herding instinct that leads sheep to flock together for safety and promote …with one another,这种本能有两个作用,并用and 连接,所以复现同义and 前面的flock together. 因此选择A. connect 8、【答案】[B] to 【解...