Constructed from materials that reflect, absorb, or diffract sound, these barriers are important for urban expansion. As urbanization increases, improvements in smart materials and more stringent ...

A "son of Concorde" aircraft that may one day fly from New York to London in 1.5 hours has reached supersonic speeds. An incredible image shows Boom Supersonic's XB-1 jet breaking the sound barrier.

noted that women’s heavy dependence on charcoal and firewood has serious consequences. “The lack of access to clean and sustainable energy is not just an environmental issue—it is a barrier ...

Written with all of the fierce intelligence and passion for truth that millions have come to expect from Amy Goodman’s reportage, Breaking the Sound Barrier is, in Arianna Huffington’s words ...

After hours: March 11 at 7:59:58 PM EDT Loading Chart for SOUN ...

Try these discussions to improve your speaking and listening. There are 20 questions in each activity - 10 for Student A and 10 for Student B. You can print out the worksheet. You can listen to the ...

Try these speed reading exercises to improve reading. You can also learn something about the news. There are reading texts at different levels. You can choose the reading speed of each text. If one ...