Об­ра­зуй­те от слова SERIOUS од­но­ко­рен­ное слово так, чтобы оно грам­ма­ти­че­ски и лек­си­че­ски со­от­вет­ство­ва­ло со­дер­жа­нию тек­ста.

The UK also works to improve the global environment and has taken global warming __________________ ever since scientists discovered the hole in the ozone layer.