Concrete mixing and unloading mainly depend on the two spiral mixing leaves, so the design of the helical mixing blades is particularly important.
混凝土的搅拌和卸载主要依靠两个螺旋搅拌叶片，因此螺旋搅拌叶片的设计尤为重要。
2
A turbine is similar to a windmill; it is a very tall tower with two or three blades (叶片) at the top.
涡轮机与风车相似，它是一个顶上有着两到三个叶片的高塔。
3
Tight, slow circuits like Monaco require very aggressive wing profiles - you will see that cars run two separate 'blades' of 'elements' on the rear wings (two is the maximum permitted).