单选题Facebook的主要创始人是（）。A 比尔·盖茨B 马克·扎克伯格C 巴菲特D 乔布斯

共用题干
1.Tired of social networking?Logging off Facebook?You're probably not the only one.Fearing for their privacy or perhaps just bored with using the site,100,000 Britons are said to have deactivated（注销）their accounts last month. And Facebook fatigue seems to be catching. Six million logged off for good in the U.S.too,figures show.Worldwide,the rate of growth has slowed for a second month in a row一and as it aims to reach its goal of one billion active users,Facebook is having to rely on developing countries to boost its numbers.The figures suggest that there could be a"natural limit" for Facebook's saturation（饱和）.There is even speculation on blogs that, as is feared for its failing rival MySpace,the website could one day "pass into oblivion"（被人遗忘）.
2.Earlier this year,executives announced that the number of Facebook accounts held in the UK had reached 30 million,accounting for about half the population.The milestone was an increase of four million from last July and represented the highest saturation of any country in Europe.
3.But times change一and last month more than 100,000 in the UK stopped using the website, figures show.In the U.S.,user numbers dropped from 155.2 million to 149.4 million throughout May.In Canada there was also a fall,of about 1.5 million users,while in Russia and Norway num-bers also fell by more than 100,000 users.
4.It's not all bad news for the site.Worldwide,Facebook is still expanding and has around 600 million users,thanks to strong growth in countries such as Mexico and Brazil.
5.According to Eric Eldon,of the website Inside Facebook,which obtained the figures through analysis of the company's advertising tools,there is a point at which the site can no longer grow, once it has established itself in a country."By the time Facebook reaches around 50 percent of the total population in a given country,growth generally slows to a halt,"he explained.

Paragraph 1_________
A:Facebook users in Britain increased a lot earlier this year.
B:Facebook seems to be faced with a gloomy future.
C:Facebook is a very popular social place for many people.
D:Users of Facebook dropped dramatically in many countries.
E:In spite of the setback in some countries,Facebook is still expanding worldwide.
F: There is a reason for the decreasing users of Facebook.