If it's illegal for someone under 21 to drink, it should be illegal for them to drink and drive. That's a no-brainer.

如果不满21岁喝酒是违法的，那他们酒后驾车也应是违法的。这太容易理解了。

《柯林斯英汉双解大词典》

I do believe that it should be illegal.

我知道这是不合法的。

youdao

We believe it should be illegal to call that stuff bread.

我认为叫那玩意儿面包是非法的。

youdao

And it voted that Oregon should be free territory, with slavery illegal.

VOA: special.2009.03.05

It should be illegal, she declared, for museums to purchase classical statuary whose provenance was unclear.

ECONOMIST: The hypocrisies of the antiquities world

Solove believes it should be illegal for employers, for example, to google prospective employees and check out their Facebook accounts.

FORBES: Confessions of an Online Stalker

"It should be illegal, " Mr. Cox said in an interview.

WSJ: Websites Accused of Privacy Violations After Personal Data Reappears