half-century

And that is equivalent to its cumulative emissionsin the past half century.So why does China emit so much?

it needs lots and lots of data.In the past half-century,marine researchers have painstakingly collected

work hard and are less lucky than we are?About a half century ago,the philosopher John Rawls wrote a book called "A Theory of Justice,"

One of the most exciting scientific findingsof the past half centuryhas been the discovery of widespread trophic cascades.

One of the biggest goals in theoretical physicsover the last half century has been reconcilingthe two into one fundamental “theory of everything."