完形填空（Reader’s Digest is a monthly magazine）

完形填空（Reader’s Digest is a monthly magazine）
Reader’s Digest is a monthly magazine.Before the 1980s,it belonged to a privately?held company,which was started in 1922 by Lila Bell Wallace and Dewitt Wallace.This magazine is small and easy to carry,just half the size of most American magazines,which caused a phrase in 2005,“America in your pocket.” It is the best?selling magazine in the USA.At present,its circulation(发行量） in the USA has reached 10 million copies and the number of the readers there is 38 million.Its global circulation outside the USA has reached 40 million people throughout more than 70 countries in 21 languages.
　　This magazine‘s focus(焦点） is not news but more of cultural views because the editors think people now can get timely news from somewhere else.They hope this magazine can give readers something that is about special personal experiences,something the readers can share with their families.In different countries,this magazine provides a window to the world for the local readers.Some parts of the magazine are about the local customs and interests of the local readers.The other parts give the local readers information from all over the world.
　　This magazine actually used to be a family business _____ the Wallaces died in the 1980s.Because they had no children,there was no one to take over the company.Sixteen years ago,this company went public and became a public company.
填空处答案是until,可不可以填before?如果不可以,为什么?

填空处可以填until,也可以填before.不过until 更加恰当.基本上两个填上去是同一个意思.