The bullet (子弹头) train D106 from Changsha to Shanghai has a short stop in Quzhou for only one minute. Named1 the letter D, the new trains run at speeds of 200 to 250 kilometers one hour. This is much2 than Z-type and T-type trains. For example, it 3 take people 12 hours to travel from Shanghai to Beijing. But now it only 4 10. The most interesting part of the bullet trains is the revolving (旋转的) seats. People can adjust (调整) their seats as they like, so that it is5 for you to talk with others around you face to face. The new trains run 6 big cities. They 7the long trips much faster and more comfortable.
However, many passengers still won’t choose the bullet trains8some reasons. The ticket9of the bullet trains are much higher. For example, a hard seat ticket from Beijing to Jinan is only 90 yuan for T-type trains. But on the bullet trains all the seats are10. And they cost 153 to 184 yuan. On the other hand, the bullet trains don’t stop at small stations.
2放出，在该溶液中一定能大量共存的离子组是
