An exoskeleton is the outer skeleton of an animal to protect them. An exoskelton is also called a shell.
Igneous rock?? sorry if this is wrong
b is the right answer because we breathe oxygen and when we breathe out we let out carbon dioxide
Hello!
If you look at a zipper, you'll see that it doesn't have a wheel or an axle. A zipper links the <span>protruding teeth that the zip contains. Your answer would be B!
You can feel free to let me know if you have any questions regarding this!
Thanks!
- TetraFish</span>