All of these applications will enhance the

问题：

All of these applications will enhance the (130) of life and spur economic growth. Over half of the U.S. work force is now in jobs that are information (131) . The telecommunication and information sector of the U.S. economy now (132) for 12 percent of the Gross Domestic Product, growing much faster than any other sector of the economy. Last year the (133) in this sector exceeded 700 billion dollars. The U.S. exported over 48 billion dollars of telecommunication equipment (134) .

A．among

B．alone

C．simple

D．single