【简答题】Social networking isn't only for the under 40s. More than 25 percent of Americans 50 years and older stay connected using sites such as Facebook, MySpace and Twitter, according to new research. 'The l...
【简答题】Social networking isn’t only for the under 40s. More than 25 percent of Americans 50 years and older stay connected using sites such as Facebook, MySpace and Twitter, according to new research. “The l...
【单选题】Although crowded cities seem to be a ______ of our crowded world, only 10 percent of the world' s people live in cities as large as Madrid or larger.