Explanation:
In thermoplastics, the arrangement of monomeric units is linear and in thermosetting plastics, it is cross-linked. Thermoplastics are usually soft, weak and less brittle, so can get soften on heating and stiffen on cooling. They can be melted, remoulded and recycled easily.
The saliva has enzymes that start to break down food using the lock and key system.The teeth chews the food and begins mechanical break down of food
The function of the limb is to help them get around and move. They might be similar in the way they’re structured? I don’t have a picture so I can’t tell. And you can assume that at one point these four animals all shared a common ancestor. Hope I helped!
Analog requires a lot of bandwidth, but digital requires less.