This paper deals with the cause of crack appearing on main landing gear axis. It shows that the cracks belong to the grinding ones.

本文对主起落架轴裂纹产生的原因进行了分析，裂纹为磨削裂纹。

youdao

And, as Euler's successor, Carl Friedrich Gauss, was to discover, if you plot real numbers on one axis of a graph and imaginary ones on the other, you create a plane that represents both sorts of numbers.

ECONOMIST: Beno?t Mandelbrot