Cloudless, that is, except for two or three long white lines smeared across the perfect blue sky by airplanes like smudges on a pane of glass.

• 无云的天空，就是，除了两三行飞机留下的白色长拖尾横跨完美的蓝色天空，就像是有脏东西在窗格玻璃上一样。