Bark is a homonym that can mean the sound a dog makes or the outer covering of a tree.

“Bark”是一个同音异义词，可以表示狗叫声或树皮。

Sugar is sweet and tasty. And a coat is the outer covering of something.

糖很甜很好吃。而外层是指某种东西的外面覆盖物。

The outer covering of the egg is waterproofed to prevent the embryo from drying out.

鸡蛋的外壳是不透水的,防止胚胎失水.

Component structure of the outer covering and flight surfaces of all modern Birds.

现代鸟类体表和翼面覆盖的结构。

Component structure of the outer covering and flight surfaces of all modern birds.

现代鸟类体表和翼面覆盖的结构。