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》

Clearly, the sale of such stuff ought to be illegal.

显然，出售此类物品应该是违法的。

youdao

Such actions would be illegal under US law.

根据美国法律，这些行为是非法的。

youdao

North of the line, slavery would be illegal.

VOA: special.2009.07.23

Do you think that downloading should be absolutely illegal and prohibited?

你觉得下载是绝对违法的，应该禁止吗？

不能非法下载 - SpeakingMax英语口语达人

So even without there being an Attorney General, somebody might be awake in the justice department and notice that that's actually illegal.

就算是司法部长不知情,司法部门也会有人会发现,这样的协议是违法的

耶鲁公开课 - 博弈论课程节选

He said members had not been balloted for strike action, so any participation would be illegal.

BBC: Council staff strike causes havoc

On Thursday, a General Accounting Office official told Congress this policy may be illegal.

FORBES: New U.S. Nuclear Waste Policy May Be Illegal: GAO

Whitehead says his construction-company clients suspect as many as half their workers may be illegal.

FORBES: Who's Gonna Do the Work?