External And Internal Disputes

External and internal intercostal muscles are present in

The convering tissue of external and internal surfaces of animals is :

The tissue that external and internal surfaces of parts of body in animals is

The tissue that covers external and internal surfaces of parts of body in animals is

Corolla aestivation showing two external, two internal and one partially external and internal sepals. The condition is

What are the differences between external and internal respiration ?