Roll out again, and once more fold in thirds to form three layers.
然后再将面团擀开，再重复之前的折叠动作，又形成新的三层。
2
When this happens uniformly across a large front, a roll cloud may form.
由于同时发生在一个面积广阔的锋面，于是就形成了这种卷云。
3
Some species simply live in the dung, while others form perfectly spherical dung balls, which they roll with their hind legs, often over large distances, to a place where they can bury it.