警方摧毁了一个被黑客控制用于发送垃圾邮件的僵尸网络。

The police dismantled a ___botnet controlled by hackers to send spam emails.

黑客利用这些被感染的设备组成僵尸网络来发起大规模的网络攻击。

Hackers use these infected devices to form ___botnets for launching large-scale cyber attacks.