警方正在开始对毒品交易进行打击。

The police are starting a ___crackdown on drug trafficking.

政府宣布对逃税行为进行严厉打击。

The government announced a ___crackdown on tax evasion.

最近对网络犯罪的打击非常有效。

The recent ___crackdown on cybercrime has been very effective.