In a pennaceous feather, the barbs grow helically around the tubular feather germ and fuse on one side to form the rachis.Simultaneously, new barb ridges form on the other side of the tube. 在正羽上,羽枝以螺旋形绕著管状的羽芽生长,在管子的一侧接合在一起形成羽轴,同时在管子的另一侧形成新的羽枝脊。
The disc-shapes are attached helically, creating a tube with a room for the nucleic acid in the middle.
圆盘沿着轴心进行螺旋排列,形成一个中间可以容纳核酸的中空管。
生活大爆炸 第4季
No misunderstanding. I've learned what that request actually means, and I don't want to be joined to another object by an inclined plane wrapped helically around an axis.