[单项选择]Half the world’’s population will be speaking or learning English by 2015, researchers say. Two billion people are expected to start learning English within a decade and three billion will speak it,says a British Council estimate. 　　Other languages, such as French, risk becoming the casualties of this "linguistic globalization". But the boom will be over by 2050 and the English-language teaching industry will have become a victim of its own success, says David Graddol, author of the report, The Future of English. 　　Mr. Graddol’’s research was based on a computer model developed to estimate demand for English-language teaching around the world. The lecturer, who has worked in education and language studies at the Open University for the past 25 years, said the model charted likely student numbers through to 2050. 　　It was compiled by looking at various estimates from the United Nations Education, Scientific and Cultural Organization (Unesco) on education provision, demographic projec
A. terminate within half a century.
B. climax in the middle of the century.
C. endure for no less than five decades.
D. quit till the beginning of the 2050s.