更多"Commuter trains are often stuffy an"的相关试题:
[单项选择] Commuter trains are often stuffy and crowded, and they frequently fail to run on time. As if that were not bad enough, physicist Hondon published a paper that gave commuters yet another reason to feel uncomfortable.
Dr. Hondon examined mobile-phone usage in enclosed spaces such as railway carriages, buses and lifts, all of which are, in essence, metal boxes. His model predicted that a large number of passengers crowded together, all talking, sending text messages, or browsing the web on their phones, could produce levels of electromagnetic radiation that exceed international safety standards. That is because the radio waves produced by each phone are reflected off the metal walls of the carriage, bus or lift. Enough radiation escapes to allow the phone to communicate with the network, but the rest fills the inside of the carriage with bouncing microwaves.
This sounds worrying. However, in a paper published recently, Jaime Ferrer and Lucas Fernández-Seivane from the Univer
A. Because he sets up a model of international radiation safety standards.
B. Because he put forward that the radiation produced by all the mobile phones in the enclosed spaces will bounce around and be harmful.
C. Because the commuters worried that the metal walls of the railway carriage will threaten their health.
D. Because the commuters are afraid that the use of mobile phone will be banned in the railway carriage.
[填空题]High-speed trains are often the fastest way to travel between city centers in Europe, beating short-haul flights for journeys of up to 550 kilometers. At speeds of up to 320 kilometers an hour, the train certainly takes the strain; compared to airports, high-speed train stations are stress-free citadels (要塞) of peace.
Trains also score well on that shifting equation of comfort, convenience and cost: On short-haul flights, flying time can be as little as 20 percent of total journey time. What counts most with mil travel is the quality of uninterrupted time from the moment you board to the time you arrive: a train station’s 10-minute average check-in time for business travelers includes going through security. Take the lap-top and do a pile of work in peace. A study shows that business travelers are willing to travel up to four hours on a high-speed train because of" increased productivity" compared with airline travel, while the limit for leisure travelers is trips of up to six h