10-05-24 What is red but green, open but closed and old but new? Answer: London's stunning new double-decker buses. 什么东西既是红色的又是绿色的（环保）？既封闭又开放？既是传统的又是新的？这就是伦敦推出的极具看点的新型双层巴士。 The new buses, which will sta...