Using long cylindrical tubes containing water, observers noted that ground tilt tended to occur before major earthquakes.

观察员使用装有水的长圆柱形管子，注意到地面倾斜往往发生在大地震之前。

For instance, carbon nanotubes, which are cylindrical tubes made of carbon atoms, are renowned for their incredible strength, yet they're as light as a feather.

例如，碳纳米管是由碳原子制成的圆柱形管，以其令人难以置信的强度而闻名，但它们却像羽毛一样轻。