High-speed rails(HSR)are playing an important role in the transportation systems across the world.In Japan,the Shinkansens carry more than 250million passengers each year.In Europe,the trans-European high-speed rail network is in operation.At the beginning of 2011,U.S.President has called for a six-year,$53 billion budget for HSR.Nowadays,China has built the world's largest HSR network of over 4 600 miles.
展开▼