If left unchecked, weeds will flourish.

如果不加以遏制，杂草就会疯长。

...a world in which brutality and lawlessness are allowed to go unchecked.

任由野蛮行径和不法行为横行无忌的世界

This provision gives the president total and unchecked power.

这条规定赋予了总统绝对及不受约束的权力。